JP2019089355A - Power steering device - Google Patents

Abstract

To reduce a manufacture cost of a power steering device.SOLUTION: A power steering device 100 includes: an input shaft 11 for inputting a steering torque from a steering wheel 1; a torsion bar 13 coupled to the input shaft 11; and a first output shaft 20 and a second output shaft 40 linked to a rack shaft 5. The first output shaft 20 and the second output shaft 40 are constituted so as to be coupled to the torsion bar 13. The torsion bar 13 is coupled to one of the first output shaft 20 and the second output shaft 40. An auxiliary torque is transmitted to the other of the first output shaft and the second output shaft from an electric motor.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power steering apparatus.

  As a power steering apparatus, Patent Document 1 discloses a pinion housing rotatably supporting a manual drive pinion on both left and right sides of a gear box in which a rack shaft is slidably fitted in an axial direction, and a motor drive pinion And a motor output shaft housing rotatably supporting the power steering device.

Japanese Utility Model Publication No. 60-151774

  In a so-called dual-pinion type power steering apparatus as disclosed in Patent Document 1, a steering-side pinion to which a steering torque is input is provided on one side in the left-right direction of the vehicle, and an auxiliary torque is input on the other side. A pinion on the assist side is provided. A steering shaft and a torque sensor are connected to the pinion to which the steering torque is input. A motor and a reduction gear are attached to the pinion to which the assist torque is input. Thus, the two pinions disposed to the left and right with respect to the center of the vehicle are generally formed in different shapes because of the difference in the components to be attached. Further, since the two pinions have different inclination angles with respect to the rack axis, the twisting directions of the teeth also differ.

  In the power steering apparatus, it is required to reduce the manufacturing cost by making the configuration common to the left-hand drive car and the right-hand drive car. However, in the dual pinion type power steering device, since the two pinions have different tooth twists, for example, in the left-hand drive car, the pinion to which the steering torque is input is diverted to the right-hand drive car and the steering torque is used as the rack shaft It is difficult to use as a pinion on the steering side to transmit.

  From the above, it is necessary to manufacture two pinions on the steering side and the assist side in each of the two types of left-hand drive car and right-hand drive car due to the difference in the mounted components and the difference in twist direction of the pinion teeth. , Had led to increased manufacturing costs.

  The present invention has been made in view of such technical problems, and an object thereof is to reduce the manufacturing cost of the power steering apparatus.

  A first invention relates to a power steering apparatus, which is linked to a rack shaft for turning wheels, an input shaft to which a steering torque from a steering wheel is input, a torsion bar connected to the input shaft, and a rack shaft A first output shaft and a second output shaft, a torque sensor for detecting a steering torque by detecting a torsion of the torsion bar, and an electric motor for generating an assist torque based on a detection result of the torque sensor, The first output shaft and the second output shaft are each configured to be connectable to a torsion bar, the torsion bar is connected to one of the first output shaft and the second output shaft, and the auxiliary torque is transmitted to the other from the electric motor It is characterized by being.

  In the first invention, both the first output shaft and the second output shaft can be connected to the torsion bar. Therefore, the steering unit including the torsion bar, the input shaft, and the torque sensor can be attached to the rack shaft via the first output shaft or the second output shaft, regardless of whether the steering wheel position is left or right. The auxiliary torque of the electric motor is input to the first output shaft or the second output shaft not connected to the torsion bar. As described above, by changing the shaft connected to the torsion bar, the steering unit can be attached to the rack shaft regardless of whether it is a left-hand drive car or a right-hand drive car, and the configuration of the power steering apparatus is made common. Can.

  A second aspect of the invention is characterized in that the first output shaft and the second output shaft are each configured to be connectable to the torsion bar, having press-fit holes into which the torsion bar can be press-fitted.

  According to a third aspect of the present invention, there is provided a case containing an input shaft, a torsion bar, and a torque sensor, a first housing rotatably supporting a first output shaft, and a second housing rotatably supporting a second output shaft. , And the case has a plurality of case holes, and the first housing has a plurality of first attachment holes, and the case can be attached by a fastening bolt inserted over the case hole and the first attachment hole The second housing has a plurality of second attachment holes, and the case is attachable to the case by a fastening bolt inserted over the case hole and the second attachment holes, and the second housing is provided between the plurality of first attachment holes. The case is attachable to both the first housing and the second housing, with the pitch and the pitch between the plurality of second mounting holes being respectively identical to the pitch between the plurality of case holes. And wherein the Rukoto.

  In the third invention, the case can be attached to both the first housing and the second housing. Therefore, a common case can be used regardless of whether the steering wheel position is left or right.

  A fourth invention is characterized in that the case has a convex portion, and the first housing and the second housing each have a concave portion to which the convex portion can be fitted.

  In the fourth invention, even when the case is attached to either the first housing or the second housing, the convex portion and the concave portion are fitted, so the case hole and the first attachment hole or the second attachment hole Can be aligned. Thus, the attachment between the case and the first and second housings is improved.

  A fifth invention further includes a reduction gear mechanism configured by a worm wheel and a worm shaft meshing with each other to reduce the rotation of the electric motor, and each of the first output shaft and the second output shaft has a pinion gear meshing with a rack gear of the rack shaft It is provided on the opposite side of the pinion portion to be formed, the press-in portion to which the worm wheel is press-fitted, and the press-in portion with respect to the press-in portion and is formed larger in diameter than the press-in portion. And a positioning portion.

  In the fifth invention, the shape of the proximal end opposite to the pinion portion with respect to the positioning portion does not affect the positioning accuracy of the worm wheel. In the power steering apparatus, the connection position between the steering wheel side and the input shaft differs depending on the steering wheel position of the vehicle. Even in such a case, by making the shapes of the proximal ends of the first output shaft and the second output shaft different from each other, the input shaft of the steering unit attached to the first output shaft or the second output shaft The position can be adjusted. Therefore, even when the common steering unit is used regardless of the position of the steering wheel, the steering wheel and the input shaft can be easily aligned and coupled.

  According to the present invention, the manufacturing cost of the power steering apparatus can be reduced.

It is a block diagram of the power steering device concerning the embodiment of the present invention. It is a sectional view showing the 1st output shaft concerning the embodiment of the present invention. It is a sectional view showing the 2nd shaft concerning the embodiment of the present invention. It is a top view which shows the attachment structure of the case which concerns on embodiment of this invention. It is a top view which shows the attachment structure of the cover which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1, the entire configuration of a power steering apparatus 100 in the present embodiment will be described. Hereinafter, the case where the power steering apparatus 100 is configured as a power steering apparatus for a left-hand drive vehicle will be described.

  The power steering apparatus 100 includes a steering mechanism 10 that steers the wheels 2 of the vehicle according to the rotation of the steering wheel 1 as a steering wheel to which a steering torque is input by the driver, and an auxiliary torque that assists the driver's steering torque. An assist mechanism 30 is provided, and a controller 50 that controls an assist amount of steering torque.

  The steering mechanism 10 is connected to the steering wheel 1 and rotates in response to the rotation of the steering wheel 1. The first steering shaft 3, the rack shaft 5 for steering the wheels 2, and the second steering shaft linked to the rack shaft 5. A steering reaction force is applied to the first steering shaft 3 in a state in which the clutch 6 as a connection switching portion for switching between connection and disconnection of the first steering shaft 3 and the second steering shaft 4 and the clutch 6 are disconnected. And a reaction force motor 61.

  The clutch 6 is an electromagnetic clutch, and disconnects the first steering shaft 3 and the second steering shaft 4 when the electromagnetic coil is excited, and mechanically isolates the first steering shaft 3 and the second steering shaft 4 when the electromagnetic coil is not excited. Connect to Steer-by-wire control is performed when the clutch 6 is disconnected, and assist control is performed when the clutch 6 is connected.

  The reaction force motor 61 is provided such that the rotor rotates with the first steering shaft 3. The driving force of the reaction force motor 61 is reduced in rotational speed by the reduction mechanism 62 and output to the first steering shaft 3. Therefore, when the reaction force motor 61 is driven with the clutch 6 disconnected, the steering reaction force is applied to the first steering shaft 3 in response to the driver's steering operation. As a result, it is possible to give a pseudo steering wheel weight to the driver's steering operation. The speed reduction mechanism 62 is a worm gear constituted by a worm wheel 62a connected to the first steering shaft 3, and a worm shaft 62b meshing with the worm wheel 62a and connected to the output shaft of the reaction force motor 61. Further, on the first steering shaft 3, a steering angle sensor 63 for detecting a steering angle which is a rotation angle of the steering wheel 1 is provided.

  The second steering shaft 4 includes an input shaft 11 connected to the clutch 6, a first output shaft 20 linked to the rack shaft 5, and a torsion bar 13 connecting the input shaft 11 and the first output shaft 20. . The first output shaft 20 is formed with a first pinion gear 22 a that meshes with the rack gear 5 a formed on the rack shaft 5. The specific configuration of the first output shaft 20 will be described in detail later.

  When the steering wheel 1 is operated with the clutch 6 connected, the first steering shaft 3 and the second steering shaft 4 rotate. This rotation is converted into linear motion by the first pinion gear 22a and the rack gear 5a, and the wheel 2 is steered via the knuckle arm 14 and the like.

  The assist mechanism 30 detects a twist angle of the torsion bar 13 to detect a steering torque, and a first assist mechanism 32 and a second assist mechanism 35 which assist the steering torque based on the detection result of the torque sensor 31. And.

  The first assist mechanism 32 applies an assist torque to the second steering shaft 4, specifically, the first output shaft 20. The first assist mechanism 32 decelerates the rotation of the first steering motor 33 and the first steering motor 33 as an electric motor that generates the assist torque based on the detection result of the torque sensor 31, and the first output shaft 20. And a first reduction gear mechanism 34 for transmitting to the vehicle.

  The first reduction gear mechanism 34 is a worm gear constituted by a worm hole (hereinafter, referred to as “first worm wheel”) 34 a and a worm shaft (hereinafter, referred to as “first worm shaft”) 34 b that mesh with each other.

  The second assist mechanism 35 is linked to the second steering motor 36 as an electric motor that generates the assist torque based on the detection result of the torque sensor 31, and the rack shaft 5, and the driving force of the second steering motor 36. The second output shaft 40 transmits the second output shaft 40 to the rack shaft 5, and the second reduction mechanism 37 transmits the second output shaft 40 by decelerating the rotation of the second steering motor 36.

  On the second output shaft 40, a second pinion gear 42a that meshes with the rack gear 5a of the rack shaft 5 is formed. The specific configuration of the second output shaft 40 will be described in detail later.

  The second reduction gear mechanism 37 is a worm gear configured by a worm hole (hereinafter, referred to as “second worm wheel”) 38 a and a worm shaft (hereinafter, referred to as “second worm shaft”) 38 b that mesh with each other.

  The controller 50 is configured by a microcomputer provided with a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), and an I / O interface (input / output interface). The RAM stores data in the processing of the CPU, the ROM stores in advance a control program of the CPU, etc., and the I / O interface is used to input and output information with the connected device. The controller 50 may be configured by a plurality of microcomputers. The controller 50 is programmed to be able to execute at least a process necessary to execute the control according to the present embodiment. The controller 50 may be configured as one device, or may be divided into a plurality of devices, and each control in the present embodiment may be configured to be distributed and processed by the plurality of devices.

  In addition to the detection signal of the steering angle sensor 63 and the detection signal of the torque sensor 31, the state information of the vehicle such as the vehicle speed is input to the controller 50.

  As described above, in the power steering device 100, the two shafts of the first output shaft 20 and the second output shaft 40 are linked to the rack shaft 5. The first output shaft 20 and the second output shaft 40 are provided separately on the left and right of the vehicle, respectively. As shown in FIG. 1, the power steering apparatus 100 of this embodiment is configured for a left-hand drive vehicle in which the steering torque from the steering wheel 1 is input to the first output shaft 20 provided relatively on the left side of the vehicle. Ru.

  Further, in the power steering device 100, the steering torque and the assist torque from the first assist mechanism 32 are input to the first output shaft 20, and the assist torque from the second assist mechanism 35 is input to the second output shaft 40. Thus, the power steering apparatus 100 is a dual pinion type having two pinion shafts (the first output shaft 20 and the second output shaft 40) linked to the rack shaft 5, and an auxiliary torque is input to each of the pinion shafts. Is a two assist type.

  Next, the operation of the power steering apparatus 100 will be described.

  In normal times, the clutch 6 is disengaged and steer-by-wire control is performed. In the steer-by-wire control, the controller 50 controls the first steering motor 33 and the second steering motor 36 in accordance with the operation state of the steering wheel 1. Thereby, the wheel 2 is steered. Specifically, the controller 50 sets a target turning angle based on the detection result of the turning angle sensor 63 and the vehicle speed, and the first turning motor so that the turning angle of the wheel 2 matches the target turning angle. 33 and the second steering motor 36 are controlled.

  Further, in the steer-by-wire control, the controller 50 controls the reaction force motor 61 in accordance with the steered state of the wheel 2 to apply a steering reaction force to the steering wheel 1. Specifically, the controller 50 sets a target steering reaction force corresponding to a reaction force received from the road surface by a steering operation, and the steering reaction force applied to the first steering shaft 3 matches the target steering reaction force. The reaction force motor 61 is controlled.

  When the controller 50 determines that there is an abnormality in its own control system, the clutch 6 is connected to switch from steer-by-wire control to assist control. When an abnormality occurs in the control system of the controller 50, the clutch 6 switches from the disconnected state to the connected state.

  First, the case where the controller 50 determines that there is an abnormality in the reaction force motor 61 and the system controlling the same will be described. In this case, the controller 50 controls the first steering motor so that an assist force for assisting the driver's steering operation is applied to the first output shaft 20 and the second output shaft 40 based on the detection result of the torque sensor 31. 33 and the second steering motor 36 are controlled. At this time, the reaction force motor 61 is disconnected from the controller 50 so as not to be a load for the steering operation, and is in a no-load state. As described above, when an abnormality occurs in the reaction force motor 61 or a system that controls the reaction force motor 61, assist control by the first and second steering motors 33 and 36 is performed.

  Next, a case where the controller 50 determines that there is an abnormality in the first and second steering motors 33 and 36 or a system controlling them will be described. In this case, the controller 50 controls the reaction force motor 61 based on the detection result of the torque sensor 31 so that an assist force for assisting the steering operation by the driver is applied to the first steering shaft 3. At this time, the first and second steering motors 33 and 36 are disconnected from the controller 50 so as not to be a load for the steering operation, and are in a no-load state. As described above, when an abnormality occurs in the first and second steering motors 33 and 36 or the system that controls them, the assist control by the reaction force motor 61 is performed. The rotational force is reduced by the reduction mechanism 62 and the driving force of the reaction force motor 61 is output to the first steering shaft 3 so that the assist control by the reaction force motor 61 can be performed.

  Next, the specific configuration of the power steering apparatus 100 will be described with reference to FIGS. 2 to 5. FIG. 2 is a cross-sectional view showing the periphery of the first output shaft 20. As shown in FIG. FIG. 3 is a cross-sectional view showing the periphery of the second output shaft 40. As shown in FIG.

  As shown in FIGS. 2 and 3, the power steering apparatus 100 rotates a gear case 70 accommodating the rack shaft 5, a first housing 71 rotatably supporting the first output shaft 20, and a second output shaft 40. A second housing 72 freely supported, and a case 73 accommodating the input shaft 11, the torsion bar 13, and the torque sensor 31 are provided.

  The gear case 70 includes a rack receiving hole 70 a for receiving the rack shaft 5, a first shaft receiving hole 70 b (see FIG. 2) for receiving a part of the first output shaft 20, and a part of the second output shaft 40. And a second shaft receiving hole 70c (see FIG. 3) in which the The first shaft accommodation hole 70 b and the second shaft accommodation hole 70 c are respectively a first pinion gear 22 a of the first pinion 22 in the first output shaft 20 described later and a second pinion gear of the second pinion 42 in the second output shaft 40. The rack housing hole 70 a is opened so that the rack gear 42 a engages with the rack gear 5 a of the rack shaft 5.

  Inside the gear case 70, there are provided two support mechanisms 86, 87 having springs 86a, 87a for urging the rack shaft 5 toward the first output shaft 20 and the second output shaft 40, respectively. One support mechanism 86 is provided on the opposite side of the rack shaft 5 to the first output shaft 20. The other support mechanism 87 is provided on the opposite side of the rack shaft 5 to the second output shaft 40. The rack shaft 5 is biased toward the first output shaft 20 and the second output shaft 40 by the support mechanisms 86 and 87, whereby the space between the rack shaft 5 and the first output shaft 20 and the second output shaft 40 is obtained. Backlash is reduced. Thus, the rattling noise when the rack shaft 5 is moved by the rotation of the first output shaft 20 and the second output shaft 40 is reduced.

  The first housing 71 and the second housing 72 are attached to the gear case 70, respectively. In the present embodiment, the first housing 71 and the second housing 72 are separately formed from the gear case 70. However, the present invention is not limited to this. The first housing 71 and the second housing 72 may be integrally formed with the gear case 70.

  As shown in FIG. 2, the first housing 71 is provided with a first accommodation hole (recess) 71 a that accommodates the first worm wheel 34 a and a part of the first output shaft 20. The first output shaft 20 is rotatably supported by the gear case 70 and the first housing 71 via a bearing 81 supported between the gear case 70 and the first housing 71.

  The first output shaft 20 has a first end portion 21 supported by the gear case 70 via a bearing 82, and a first pinion portion 22 in which a first pinion gear 22a meshing with the rack gear 5a of the rack shaft 5 is formed. A first press-fit portion 23 to which the first worm wheel 34a of the reduction gear mechanism 34 is press-fit, a first positioning portion 24 formed to have a diameter larger than the first press-fit portion 23 and positioning the first worm wheel 34a, and a torsion bar 13 And a first base end 25 in which a first press-in hole 27 is formed. In the first output shaft 20, the first positioning portion 24, the first press-fit portion 23, the first pinion portion 22, and the first tip portion 21 are provided in this order toward the tip side (the non-input shaft side). Is formed in a step-like shape in which the outer diameter is reduced. The first output shaft 20 is connected to the input shaft 11 via the torsion bar 13 by the torsion bar 13 being press-fitted into the first press-in hole 27 provided in the first base end 25.

  A first step surface 26 is formed between the first positioning portion 24 and the first press-fit portion 23. The first worm wheel 34 a of the first reduction gear mechanism 34 is press-fit into the first press-fit portion 23 until it abuts on the first step surface 26. As a result, the first worm wheel 34a is positioned at an appropriate position to mesh with the first worm shaft 34b.

  The case 73 has a support hole 73 a through which the input shaft 11 is inserted, and an accommodation recess 73 b for accommodating the input shaft 11, the torsion bar 13, and the torque sensor 31. Hereinafter, the input shaft 11, the torsion bar 13, and the torque sensor 31 are collectively referred to as a "steering unit".

  The input shaft 11 is rotatably supported by the bearing 83 on the case 73. One end of the input shaft 11 protrudes from the case 73 through the support hole 73 a and is connected to the first steering shaft 3 via a universal joint (not shown) and the clutch 6.

  One end of the torsion bar 13 is inserted into and coupled to the input shaft 11. At the other end of the torsion bar 13, a serration portion 13a is formed on the outer periphery of which serration processing is performed. The serration portion 13 a is press-fit into the first press-fit hole 27 of the first output shaft 20.

  The torque sensor 31 is provided across the input shaft 11 and the first output shaft 20. The torque sensor 31 can adopt a known configuration, so the illustration and detailed description of the specific configuration will be omitted.

  As shown in FIGS. 2 and 4, the case 73 and the first housing 71 are connected by a plurality of (three in the present embodiment) fastening bolts 90. As shown in FIG. 2, the case 73 is formed with a first case hole 73 c through which each fastening bolt 90 is inserted. In the first housing 71, internal threads are formed on the inner periphery, and a first mounting hole 71c to which each fastening bolt 90 can be screwed is formed at a position corresponding to the first case hole 73c of the case 73. The fastening bolt 90 is inserted into the first case hole 73 c of the case 73 and screwed into the first mounting hole 71 c of the first housing 71, whereby the case 73 is attached to the first housing 71.

  Further, the case 73 is provided with a first annular convex portion 73 d (convex portion) fitted in the opening 71 b of the first accommodation hole 71 a of the first housing 71. The first annular convex portion 73 d of the case 73 is fitted in the first accommodation hole 71 a of the first housing 71 to form an inlay structure, whereby the first case hole 73 c and the first case hole 73 c in the radial direction of the first output shaft 20 are formed. The mounting holes 71c are aligned. Therefore, the attachment between the case 73 using the fastening bolt 90 and the first housing 71 is improved.

  As shown in FIG. 3, the second housing 72 is provided with a second accommodation hole 72 a for accommodating a part of the second output shaft 40 and the second worm wheel 37 a. The second output shaft 40 is rotatably supported by the gear case 70 and the second housing 72 via a bearing 84 supported between the gear case 70 and the second housing 72.

  The second output shaft 40 has a second end portion 41 supported by the bearing 85 on the gear case 70, and a second pinion portion 42 in which a second pinion gear 42a meshing with the rack gear 5a of the rack shaft 5 is formed. 37. A second press-in portion 43 into which the second worm wheel 37a of 37 is press-fit, a second positioning portion 44 which is larger in diameter than the second press-in portion 43 and positions the second worm wheel 37a, and serrations of the torsion bar 13. And a second base end 45 in which a second press-in hole 47 in which the portion 13a can be press-fitted is formed. In the second output shaft 40, the second positioning portion 44, the second press-fit portion 43, the second pinion portion 42, and the second tip portion 41 are provided in this order toward the tip side, and the outer diameter decreases in this order It is formed in steps.

  A second step surface 46 is formed between the second positioning portion 44 and the second press-fit portion 43. The second worm wheel 37 a of the second reduction gear mechanism 37 is press-fit into the second press-fit portion 43 until it abuts on the second step surface 46. As a result, the second worm wheel 37a is positioned at an appropriate position to mesh with the second worm shaft 37b.

  As shown in FIGS. 3 and 5, a cover 74 for sealing the second accommodation hole 72a is attached to the second housing 72. The cover 74 and the second housing 72 are connected by three fastening bolts 90. As shown in FIG. 3, the cover 74 is formed with three second case holes 74 c through which the fastening bolts 90 are inserted. An internal thread is formed on the inner periphery of the second housing 72, and three second mounting holes 72c to which the fastening bolts 90 can be screwed are formed at positions corresponding to the second case holes 74c. The fastening bolt 90 is inserted into the second case hole 74 c of the cover 74 and screwed into the second mounting hole 72 c of the second housing 72, whereby the cover 74 is attached to the second housing 72.

  The relative positional relationship between the first mounting holes 71c of the case 73 (the pitch between the first mounting holes 71c) is the relative positional relationship between the second mounting holes 72c of the cover 74 (the spacing between the second mounting holes 72c). Match the pitch). In the present embodiment, as shown in FIG. 4 and FIG. 5, since the first mounting holes 71c and the second mounting holes 72c are respectively arranged on the same circumference, the pitch angle α1 at which the first mounting holes 71c are formed , Β1 coincide with the pitch angles α2, β2 at which the second attachment holes 72c are formed, respectively. Therefore, the first case hole 73c and the second case hole 74c are also provided at the same pitch angle as the first mounting hole 71c and the second mounting hole 72c. That is, the attachment structure of the case 73 and the first housing 71 and the attachment structure of the cover 74 and the second housing 72 are similar to each other.

  Therefore, the case 73 can be attached to the first housing 71 by the fastening bolt 90 and can also be attached to the second housing 72. Similarly, the cover 74 can also be attached to the second housing 72 by means of the fastening bolts 90 and also to the first housing 71.

  Further, as shown in FIG. 3, the cover 74 is formed with a base end accommodation recess 74 a for accommodating the second base end 45 of the second output shaft 40. The cover 74 has a second annular convex portion (convex portion) 74 b fitted in the opening 72 b of the second accommodation hole 72 a of the second housing 72. The second annular projection 74b of the cover 74 is engaged with the second accommodation hole 72a of the second housing 72 to form an inlay structure, whereby the second case hole 74c and the second case hole 74c in the radial direction of the second output shaft 40 are formed. The mounting holes 72c are aligned. Therefore, the attachment between the cover 74 and the second housing 72 using the fastening bolt 90 is improved.

  The opening 71 b of the first accommodation hole 71 a of the first housing 71 and the opening 72 b of the second accommodation hole 72 a of the second housing 72 have the same inner diameter. The first annular convex portion 73 d of the case 73 and the second annular convex portion 74 b of the cover 74 have the same outer diameter.

  Here, due to the limitation of the layout in the vehicle, the first output shaft 20 and the second output shaft 40 may be provided to be inclined in the left-right direction without being provided orthogonal to the rack shaft 5 . Further, the first pinion gear 22 a of the first output shaft 20 is formed so as to twist with respect to the center of the first output shaft 20 in order to make the meshing of the rack shaft 5 with the rack gear 5 a smooth. Similarly, the second pinion gear 42 a of the second output shaft 40 is formed so as to twist with respect to the center of the second output shaft 40. Since the first output shaft 20 and the second output shaft 40 have different inclination directions with respect to the rack shaft 5, the twist directions of the first pinion gear 22a and the second pinion gear 42a also differ.

  On the other hand, there is a demand for the power steering apparatus 100 to reduce the cost by making the configuration common between when mounted on a left-hand drive vehicle and when mounted on a right-hand drive vehicle.

  However, since the first output shaft 20 and the second output shaft 40 have different twists of the first pinion gear 22a and the second pinion gear 42a, the left and right positions of the first output shaft 20 and the second output shaft 40 are simply interchanged and used It is difficult to do.

  So, in this embodiment, both the 1st output shaft 20 and the 2nd output shaft 40 are comprised so that connection with the torsion bar 13 is possible. Specifically, the first output shaft 20 and the second output shaft 40 respectively have a first press-in hole 27 and a second press-in hole 47 in which the serration portion 13a of the torsion bar 13 can be press-fitted.

  Thus, the steering unit including the input shaft 11, the torsion bar 13 and the torque sensor 31 can be attached to the first output shaft 20 on the left side of the vehicle as in the above embodiment, and the second output shaft on the right side It can be attached to 40. When the power steering apparatus 100 is configured for a right-hand drive vehicle, the steering unit may be attached to the second output shaft 40 without attaching the first output shaft 20, contrary to the present embodiment.

  As described above, in the power steering apparatus 100, the common first output shaft 20 is used on the left side of the vehicle and the common second output shaft 40 is used on the right side in both the right-hand drive car and the left-hand drive car. be able to. Since the first output shaft 20 and the second output shaft 40 can be commonly used regardless of the position of the steering wheel, the manufacturing cost of the power steering device 100 can be reduced.

  Further, the pitch between the first mounting holes 71 c in the first housing 71 matches the pitch between the second mounting holes 72 c in the second housing 72. Thus, the case 73 can be attached to both the first housing 71 and the second housing 72, and the cover 74 can also be attached to both the first housing 71 and the second housing 72. Therefore, even when the steering unit is attached to either the first output shaft 20 or the second output shaft 40, in other words, the power steering apparatus 100 is configured for either the left-hand drive vehicle or the right-hand drive vehicle. Even if so, a common case 73 and cover 74 can be used. Therefore, the manufacturing cost of power steering apparatus 100 can be further reduced.

  Furthermore, the first annular convex portion 73 d of the case 73 and the second annular convex portion 74 b of the cover 74 are formed to have the same outer diameter. The opening 71b of the first accommodation hole 71a in the first housing 71 and the opening 72b of the second accommodation hole 72a in the second housing 72 are formed to have the same inner diameter. Therefore, the first annular convex portion 73 d of the case 73 can be fitted to both the first accommodation hole 71 a of the first housing 71 and the second accommodation hole 72 a of the second housing 72. Similarly, the second annular convex portion 74 b of the cover 74 can be fitted to both the first accommodation hole 71 a of the first housing 71 and the second accommodation hole 72 a of the second housing 72.

  Therefore, even when the case 73 is attached to either the first housing 71 or the second housing 72, the first annular convex portion 73d forms an inlay structure with the first accommodation hole 71a or the second accommodation hole 72a. The first case hole 73c and the first attachment hole 71c or the second attachment hole 72c are aligned. Similarly, even when the cover 74 is attached to either the first housing 71 or the second housing 72, the second annular convex portion 74b forms an inlay structure with the first accommodation hole 71a or the second accommodation hole 72a. Thus, the second case hole 74c is aligned with the first attachment hole 71c or the second attachment hole 72c. Therefore, regardless of whether the power steering apparatus 100 is configured for the left-hand drive vehicle or the right-hand drive vehicle, the case 73 and the cover 74 can easily be attached to the first housing 71 and the second housing 72 while being common Can be

  Further, the first output shaft 20 and the second output shaft 40 have a first positioning portion 24 and a second positioning portion 44 for positioning the first worm wheel 34a and the second worm wheel 37a, respectively. Thus, the first and second worm wheels 34a and 37a can be used as the first output shaft 20 and the first and second worm wheels 34a and 37a while securing the meshing accuracy between the first and second worm wheels 34a and 37a and the first and second worm shafts 34b and 37b. It can be attached to the second output shaft 40.

  Here, the layout of the in-vehicle space may be different between the left-hand drive car and the right-hand drive car. For example, the position of the universal joint for connecting the input shaft 11 and the first steering shaft 3 may be closer to the steering wheel 1 (upper side of the vehicle) of the left-hand drive vehicle. In such a case, the first output shaft 20 to which the steering unit is attached in the left-hand drive vehicle has a length between the first positioning portion 24 and the end face of the first proximal end 25 than the second output shaft 40 The length is formed long according to the difference in the position of the universal joint. Thereby, the distances between the first and second worm wheels 34a and 37a of the first and second output shafts 20 and 40 and the universal joint can be made to coincide with each other. Therefore, the left steering wheel and the right steering wheel use a common steering unit, and the input shaft 11 and the universal joint can be easily aligned and coupled. Even in such a case, since the first worm wheel 34 a and the second worm wheel 37 a are positioned by the first positioning portion 24 and the second positioning portion 44, the shape of the base end side is the first It does not affect the positioning accuracy of the worm wheel 34a and the second worm wheel 37a.

  Next, a modification of the present embodiment will be described.

  In the above embodiment, the torsion bar 13 is configured to be connectable to both the first output shaft 20 and the second output shaft 40, and the case 73 and the cover 74 respectively have the first housing 71 and the second housing 72. It is configured to be attachable to both. On the other hand, the case 73 and the cover 74 may not necessarily be configured to be attachable to both the first housing 71 and the second housing 72. If at least the torsion bar 13 is configured to be connectable to both the first output shaft 20 and the second output shaft 40, the common first output shaft 20 and the second output shaft 40 can be used regardless of the handle position. Because it can be used, manufacturing costs can be reduced.

  In the above embodiment, the serration portion 13a of the torsion bar 13 is configured to be press-fitable into the first press-fit hole 27 of the first output shaft 20 and the second press-fit hole 47 of the second output shaft 40. 13 is configured to be connectable to both the first output shaft 20 and the second output shaft 40. On the other hand, as long as the torsion bar 13 can be connected to the first output shaft 20 and the second output shaft 40, the configuration is not limited to the configuration in which the serration portion 13a is press-fit, and may be another configuration. For example, the end of the torsion bar 13 which is simply formed in a cylindrical shape without serration processing may be press-fit into the first press-in hole 27 and the second press-in hole 47.

  Further, in the above embodiment, the first output shaft 20 and the second output shaft 40 have the first positioning portion 24 and the second positioning portion 44, respectively. On the other hand, the first positioning portion 24 and the second positioning portion 44 are provided when the engagement accuracy between the first and second worm wheels 34a and 37a and the first and second worm shafts 34b and 37b can be secured. It does not have to be.

  Further, in the above embodiment, the pitches of the first attachment holes 71c of the first housing 71, the second attachment holes 72c of the second housing 72, the first case holes 73c of the case 73, and the second case holes 74c of the cover 74 are respectively pitched. Are formed three by three to match. The case 73 and the cover 74 and the first housing 71 and the second housing 72 are attached by three fastening bolts 90. On the other hand, when each of the case 73 and the cover 74 is configured to be attachable to both the first housing 71 and the second housing 72, it may be configured to form holes more than the number of the fastening bolts 90. That is, a combination of the case hole and the mounting hole through which the fastening bolt 90 is inserted or screwed may be arbitrarily selected, and the case 73 and the cover 74 may be attached to the first housing 71 and the second housing 72. . For example, in the case where the case 73 is attached to the first housing 71, six first case holes 73c and six first attachment holes 71c are formed, and an arbitrary three sets of the first case holes 73c are used. It may be configured to be fastened at According to this, since the hole through which the fastening bolt 90 is inserted can be selected, the mounting position of the case 73 can be changed by rotating the case 73 relative to the first housing 71. Further, for example, the mounting posture of the case 73 can be changed depending on whether the case 73 is attached to the first housing 71 or to the second housing 72. Thereby, the freedom degree of design (attachment) of case 73, cover 74, the 1st housing 71, and the 2nd housing 72 can be improved.

  Moreover, in the said embodiment, the power steering apparatus 100 is a steer-by-wire system and a 2 assist type. On the other hand, if the power steering apparatus 100 is a dual-pinion type having two pinions, for example, the mechanical type or the one with an electric motor assists the pinion shaft to which the steering unit is not attached. The present invention may be applied to one assist type that applies torque.

  Further, in the above embodiment, no female screw is formed in the first case hole 73c of the case 73, and a female screw is formed in the first mounting hole 71c and the second mounting hole 72c of the first housing 71 and the second housing 72. The fastening bolt 90 is formed so as to be screwable. Not limited to this, if the case 73 can be attached to the first housing 71 and the second housing 72 by the fastening bolt 90, a female screw is formed in the first case hole 73c, and the first attachment hole 71c and the second attachment hole 72c. May be a hole in which no internal thread is formed. Further, the first case hole 73c, the first attachment hole 71c, and the second attachment hole 72c are formed as through holes in which internal threads are not formed, respectively, and the case 73 is a first through the fastening bolt 90 and the nut which insert these. It may be configured to be attachable to the housing 71 and the second housing 72. Thus, the case 73 is configured to be attachable to the first housing 71 by the fastening bolt 90 inserted across the first case hole 73c and the first attachment hole 71c, and the first case hole 73c and the second attachment are formed. The configuration of the hole can be arbitrary as long as the case 73 is configured to be attachable to the second housing 72 by the fastening bolt 90 inserted through the hole 72c. The second case hole 74 c of the cover 74 is also similar to the first case hole 73 c of the case 73.

  According to the above embodiment, the following effects can be obtained.

  In the power steering apparatus 100, the torsion bar 13 is configured to be connectable to both the first output shaft 20 and the second output shaft 40. Thus, the steering unit including the input shaft 11, the torque sensor 31 and the torsion bar 13 can be attached to the first output shaft 20 as well as to the second output shaft 40. Thereby, in either the right-hand drive vehicle or the left-hand drive vehicle, the common first output shaft 20 can be used on the left side of the vehicle and the common second output shaft 40 can be used on the right side. Therefore, regardless of the position of the steering wheel, the first output shaft 20 and the second output shaft 40 can be used in common, and the manufacturing cost of the power steering apparatus 100 can be reduced.

  Further, in the power steering apparatus 100, since the pitch between the first mounting holes 71c in the first housing 71 and the pitch between the second mounting holes 72c in the second housing 72 coincide with each other, the input shaft 11 and the torque sensor 31 The housing 73 can be attached to both the first housing 71 and the second housing 72. Similarly, the cover 74 can also be attached to both the first housing 71 and the second housing 72. Therefore, the common case 73 and the cover 74 can be used in both the right-hand drive car and the left-hand drive car, and the manufacturing cost of the power steering apparatus 100 can be further reduced.

  Further, the first annular convex portion 73 d of the case 73 is formed to be able to be fitted to both the first accommodation hole 71 a of the first housing 71 and the second accommodation hole 72 a of the second housing 72. The second annular convex portion 74b of the cover 74 is also formed to be fittable to both the first accommodation hole 71a and the second accommodation hole 72a. Therefore, even when the common case 73 and the cover 74 are attached to any of the first housing 71 and the second housing 72, the first case hole 73c and the second case hole 74c, the first attachment hole 71c and the The two mounting holes 72c can be easily aligned. Therefore, the attachment property of the case 73 and the cover 74, and the 1st housing 71 and the 2nd housing 72 is securable, reducing a manufacturing cost.

  Moreover, the position of the universal joint connected with the 1st steering shaft 3 may differ in the case of a left-hand drive car and the case of a right-hand drive car. On the other hand, in the power steering apparatus 100, the first output shaft 20 and the second output shaft 40 respectively position the first positioning portion 24 and the second positioning portion 44 for positioning the first worm wheel 34a and the second worm wheel 37a. Have. Thereby, in the first output shaft 20 and the second output shaft 40, the shape of the base end side of the first positioning portion 24 and the second positioning portion 44 is the positioning accuracy of the first worm wheel 34a and the second worm wheel 37a. It can have any shape without affecting the Therefore, in the first output shaft 20 and the second output shaft 40, the shapes on the proximal end side of the first positioning portion 24 and the second positioning portion 44 are made different from each other, and the first worm wheel 34a and the second worm wheel 37a The respective distances to the universal joint can be configured to be equal to one another. Therefore, even in the case where the common steering unit is attached to either the first output shaft 20 or the second output shaft 40, the input shaft 11 and the universal joint can be easily made without using a method such as using a spacer. It can be linked.

  Hereinafter, the configuration, operation, and effects of the embodiment of the present invention will be collectively described.

  The power steering apparatus 100 is linked to a rack shaft 5 for turning the wheels 2, an input shaft 11 to which a steering torque from the steering wheel 1 is input, a torsion bar 13 connected to the input shaft 11, and a rack shaft 5 Based on the detection results of the first output shaft 20 and the second output shaft 40, the torque sensor 31 for detecting the steering torque by detecting the torsion of the torsion bar 13, and the electric motor for generating the auxiliary torque (The first steering motor 33 and the second steering motor 36), and the first output shaft 20 and the second output shaft 40 are configured to be connectable to the torsion bar 13, respectively. A torsion bar 13 is connected to one side (first output shaft 20) of the second output shaft 40, and the other Auxiliary torque is transmitted from the electric motor (the second output shaft 40) (second steering motors 36).

  In this configuration, both the first output shaft 20 and the second output shaft 40 can be connected to the torsion bar 13. Therefore, the steering shaft unit including the torsion bar 13, the input shaft 11, and the torque sensor 31 can be rack shaft 5 via the first output shaft 20 or the second output shaft 40 regardless of whether the steering wheel position is left or right. Can be attached to The auxiliary torque of the electric motor (second steering motor 36) is input to the first output shaft 20 or the second output shaft 40 not connected to the torsion bar 13. As described above, by changing the shaft connected to the torsion bar 13, the steering unit can be attached to the rack shaft 5 regardless of whether it is a left-hand drive car or a right-hand drive car. Therefore, the configuration of power steering apparatus 100 can be made common, and the manufacturing cost can be reduced.

  Further, in the power steering apparatus 100, the first output shaft 20 and the second output shaft 40 have press-fit holes (the first press-in hole 27 and the second press-in hole 47) which can press-fit the torsion bar 13 respectively. It is configured to be connectable with the bar 13.

  The power steering apparatus 100 further includes a case 73 accommodating the input shaft 11, the torsion bar 13, and the torque sensor 31, a first housing 71 rotatably supporting the first output shaft 20, and a second output shaft 40. The case 73 has a plurality of first case holes 73c, and the first housing 71 has a plurality of first attachment holes 71c. The case 73 is configured to be attachable by a fastening bolt 90 inserted over the 73c and the first attaching hole 71c, and the second housing 72 has a plurality of second attaching holes 72c into which the fastening bolt 90 can be screwed. The case 73 is configured to be attachable by the fastening bolt 90 inserted through the case hole 73c and the second mounting hole 72c. The case 73 is mounted on both the first housing 71 and the second housing 72, with the pitch between the holes 71c and the pitch between the plurality of second mounting holes 72c being identical to the pitch between the plurality of first case holes 73c. Configured to be possible.

  In this configuration, the case 73 can be attached to both the first housing 71 and the second housing 72. Therefore, the common case 73 can be used regardless of whether the steering wheel position is left or right. Therefore, the manufacturing cost of power steering apparatus 100 can be further reduced.

  Further, in the power steering apparatus 100, the case 73 has a cylindrically formed first annular convex portion 73d, and the first housing 71 and the second housing 72 can be fitted with the first annular convex portion 73d, respectively. The first accommodation hole 71a and the second accommodation hole 72a.

  In this configuration, even when the case 73 is attached to either the first housing 71 or the second housing 72, the first annular convex portion 73d and the first accommodation hole 71a or the second accommodation hole 72a are engaged with each other. The first case hole 73c can be aligned with the first attachment hole 71c or the second attachment hole 72c. Therefore, the attachment between the case 73 and the first housing 71 and the second housing 72 is improved.

  Further, the power steering apparatus 100 is configured of a worm wheel (first worm wheel 34a, second worm wheel 37a) and a worm shaft (first worm shaft 34b, second worm shaft 37b) that mesh with each other, and is an electric motor (first rotation). The first output shaft 20 and the second output shaft 40 further include a reduction mechanism (first reduction mechanism 34, second reduction mechanism 37) for decelerating the rotation of the rudder motor 33, second steering motor 36). A pinion portion (first pinion portion 22, second pinion portion 42) formed with pinion gears (first pinion gear 22a, second pinion gear 42a) engaged with the rack gear 5a of the rack shaft 5 and a worm wheel (first worm wheel 34a, The press-fit portion (the second worm wheel 37a) is press-fit The first press-fit portion 23, the second press-fit portion 43) and the press-fit portion (the first press-fit portion 23, the second press-fit portion 43) are opposite to the pinion portion (the first pinion portion 22, the second pinion portion 42) Positioning provided on the side and larger in diameter than the press-fit parts (first press-fit part 23 and second press-fit part 43) and positioning to abut against the worm wheel (first worm wheel 34a, second worm wheel 37a) And (a first positioning unit 24 and a second positioning unit 44).

  In this configuration, the shape of the base end side opposite to the pinion portion (the first pinion portion 22 and the second pinion portion 42) with respect to the positioning portion (the first positioning portion 24 and the second positioning portion 44) It does not affect the positioning accuracy of the first worm wheel 34a and the second worm wheel 37a). Therefore, by making the shapes of the proximal end sides of the first output shaft 20 and the second output shaft 40 different from each other, a universal joint connected to the steering wheel 1 is connected to the worm wheel (the first worm wheel 34a, the second worm wheel 37a The distances to) can be equal to one another. Therefore, even when the left steering wheel and the right steering wheel use a common steering unit, the universal joint and the input shaft 11 can be easily connected.

  As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only one of the example of application of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

  DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Wheel, 5 ... Rack shaft, 5a ... Rack gear, 11 ... Input shaft, 13 ... Torsion bar, 20 ... 1st output shaft, 22 ... 1st pinion part (pinion part), 22a ... 1st Pinion gear (pinion gear) 23, 23 first press-fit portion (press-fit portion) 24, 24 first positioning portion (positioning portion) 27, 27 first press-fit hole (press-fit hole) 31, torque sensor 33, first steering motor (Electric motor), 34: first reduction mechanism (reduction mechanism), 34a: first worm wheel (worm wheel), 34b: first worm shaft (worm shaft), 36: second steering motor (electric motor), 37: Second speed reduction mechanism (speed reduction mechanism), 37a: second worm wheel (worm wheel), 37b: second worm shaft (worm shaft), 4 0 ... 2nd output shaft, 42 ... 2nd pinion part (pinion part), 42a ... 2nd pinion gear (pinion gear), 43 ... 2nd press fit part (press fit part) 44 ... 2nd positioning part (positioning part), 47 ... second press-in hole (press-in hole), 70 ... gear case, 71 ... first housing, 71a ... first accommodation hole (recessed portion), 71c ... first attachment hole, 72 ... second housing, 72a ... second accommodation hole ( Recesses) 72c: second mounting hole 73: case 73c: first case hole (case hole) 73d: first annular convex portion (convex) 90: fastening bolt 100: power steering device

Claims (5)

A rack shaft that turns the wheels,
An input shaft to which steering torque from the steering wheel is input;
A torsion bar coupled to the input shaft;
A first output shaft and a second output shaft linked to the rack shaft;
A torque sensor that detects the twisting of the torsion bar to detect the steering torque;
An electric motor that generates an auxiliary torque based on the detection result of the torque sensor,
The first output shaft and the second output shaft are configured to be connectable to the torsion bar, respectively.
A power steering apparatus, wherein the torsion bar is connected to one of the first output shaft and the second output shaft, and an auxiliary torque is transmitted from the electric motor to the other.   The power according to claim 1, wherein the first output shaft and the second output shaft have press-fit holes into which the torsion bar can be press-fitted respectively, and are configured to be connectable with the torsion bar. Steering device. A case for accommodating the input shaft, the torsion bar, and the torque sensor;
A first housing rotatably supporting the first output shaft;
And a second housing rotatably supporting the second output shaft.
The case has a plurality of case holes,
The first housing has a plurality of first attachment holes, and the case can be attached by a fastening bolt inserted across the case hole and the first attachment hole.
The second housing has a plurality of second attachment holes, and the case can be attached by the fastening bolt inserted over the case hole and the second attachment hole.
The pitch between the plurality of first mounting holes and the pitch between the plurality of second mounting holes correspond to the pitch between the plurality of case holes, respectively, and the case is formed of the first housing and the second housing. The power steering apparatus according to claim 1, wherein the power steering apparatus is configured to be attachable to both. The case has a convex portion,
The power steering apparatus according to claim 3, wherein the first housing and the second housing each have a concave portion to which the convex portion can be fitted. It further comprises a speed reduction mechanism constituted by a mutually interengaging worm wheel and worm shaft for decelerating the rotation of the electric motor,
Each of the first output shaft and the second output shaft is
A pinion portion in which a pinion gear that meshes with the rack gear of the rack shaft is formed;
A press-fit portion into which the worm wheel is press-fitted;
A positioning portion which is provided on the side opposite to the pinion portion with respect to the press-fitting portion and which is formed to have a diameter larger than that of the press-fitting portion and which abuts and positions the worm wheel. The power steering device according to any one of 1 to 4.

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