JP6089720B2 - Hydraulic control device - Google Patents

Description

  The present invention provides an oil pump that sucks and discharges hydraulic oil by rotational operation, a pressure reducing valve that adjusts the pressure of the discharged hydraulic oil, and supplies hydraulic oil regulated by the pressure reducing valve to the downstream actuator. The present invention also relates to a hydraulic control device that includes an electromagnetic valve that shuts off, and that performs switching of power transmission of an automobile using oil pressure.

Conventionally, this type of automatic transmission switches the rotational speed and direction of rotation conduction to the tires that transmit the output from the engine, which is the power source, to the road surface. This is an automatic operation to detach the.
An automatic transmission is generally composed of a starting element such as a torque converter or an electromagnetic clutch, a shifting element such as a planetary gear or a clutch, and a hydraulic control element including a control valve and an oil pump for hydraulically operating them. Multistage gear shifting elements have also progressed, and on the other hand, continuously variable transmissions in which the shifting elements are converted into pulleys and belts have become mainstream.

Next, the hydraulic control element will be described with a general example. The oil pump, which is the hydraulic source, is rotated by the output shaft from the engine or an electric motor, sucks the hydraulic fluid such as automatic fluid that has accumulated in the lower oil pan, and below or to the side of the automatic transmission due to the layout. Supply to the arranged control valve.
The control valve housing is generally composed of an aluminum die-cast body divided into two parts, and a separate plate sandwiched between the bodies. A passage is formed, and a plurality of spools for switching the flow direction of the pressure oil flowing through the oil passage or reducing the pressure oil to an appropriate pressure are movably provided.
The operation of these spools is controlled by a spring member or an electromagnetic valve, which is provided on the side of the body connected to the spool by a control pressure circuit. The solenoid valve is operated by a computer command that stores the operation program, and the spool or solenoid valve itself switches the oil path so that the pressure oil from the oil pump is adjusted by the pressure reducing valve and the clutch provided in the transmission element Control the operation of actuators such as brakes.

Further, the above-described oil pump and control valve used in the automatic transmission will be described in more detail. For automatic transmission connected to the engine to rotate at a constant Direction, the input shaft is always rotated in a predetermined direction, the oil pump operates only in rotation in one direction. Even in the case of an electric pump, it operates only with rotation in the same direction.
The pressure oil discharged from the oil pump does not need to be supplied from the control valve to the actuator, or if it is surplus, it will continue to rise, so a pressure reducing valve (also called a reducing valve) called a regulator is always provided. Yes. This often serves as a safety valve as a function to prevent circuit breakage due to pressure rise, and a mechanical structure that does not use electricity that does not easily fail, that is, a structure of a spring member and a spool is generally used.

Examples of the oil pump used in the automatic transmission include a vane pump that can change the flow rate, an external gear pump that is advantageous in layout, and an internal gear pump that has a simple structure and is arranged on the input shaft.
The internal gear pump according to the present invention will be described.
An internal gear pump is rotatably accommodated in a rotor pocket of a pump housing, and has a ring-shaped outer rotor having internal teeth and an inner rotor having external teeth that mesh with the internal teeth of the outer rotor. The center of rotation is arranged in an eccentric state. The inner rotor is driven to rotate by engaging with the rotation shaft, and the outer rotor is arranged eccentrically with respect to the inner rotor, so that a suction area space is formed in a region where the meshing gap between both teeth is increased, A discharge area space is formed in an area where the meshing gap between both teeth is reduced by the rotation. The suction area space is connected to a suction port formed in the pump housing and / or a cover matched therewith, and sucks in the stored pressure oil by gradually expanding the volume by the rotation of both rotors. On the other hand, the discharge area space is connected to a discharge port formed in the pump housing and / or a cover adapted to the pump housing, and the volume of the meshing gap is supplied to the control valve by gradually reducing the volume as the rotors rotate. .

The pressure oil supplied to the control valve is adjusted to the pressure required by the pressure reducing valve as described above. However, since the oil pump is discharged by meshing the gears, the teeth of the inner rotor are rotated per rotation. Hydraulic pulsation occurs for several minutes. The larger the capacity of one tooth and the smaller the number of teeth per revolution, the smaller the advantage. However, as a contradiction, the hydraulic pulsation tends to increase, and the pressure reducing valve is affected by this hydraulic pulsation and resonates. There is a part that is easy to do. That is, since the oil pump is synchronized with the engine speed, the oil pump rotates at a wide speed of 0 to 7000 rpm, and the pressure reducing valve constituted by the spring member resonates while pulsation occurs in the entire region. Will exist. Since hydraulic pulsation adversely affects circuit strength and function in hydraulic control, an orifice for reducing hydraulic pulsation is provided in the control valve body in the feedback circuit of the pressure reducing valve.
For example, a pressure reducing valve having a spool structure will be explained. A spool that is normally closed by the elastic force of a spring member is provided, and a feedback circuit is provided in a portion where one end of the spool is configured with a small diameter to introduce pressure. A structure that keeps the pressure constant by returning the raised pressure oil (primary side) to the suction side or drain when the force over the spring member is generated due to the differential force generated by the difference in spool diameter. Is.
Here, if hydraulic pulsation occurs, the feedback circuit also affects the hydraulic pulsation and the spool vibrates. Furthermore, if the vibration system of the pressure reducing valve coincides, it will resonate. An orifice is provided between the feedback circuits. As a result, the hydraulic pulsation is attenuated, and the movement of the spool is not affected by the hydraulic pulsation, so that the downstream pressure oil (secondary side), so-called line pressure, becomes stable.

As described above, it has been explained that an orifice is provided in the feedback circuit of the pressure reducing valve as a structure that suppresses the influence of the hydraulic pulsation described above. In consideration of workability, it is difficult to drill a hole perpendicular to the circuit. That is, since the circuit is formed by casting, it is impossible to cast the hole by casting the circuit with a lid.
For this reason, as a solution, an orifice is provided in a separate plate that is sandwiched between two bodies to connect and shield a hydraulic circuit (see, for example, Patent Document 1), or the shape of a wall to be cast is inclined. Prior examples such as a structure for drilling an orifice in an oblique direction (for example, refer to Patent Document 2) and a process for forming a feedback circuit by casting to process the orifice while closing the discarded hole are disclosed. (For example, refer to Patent Document 3).

However, as described in Patent Document 1, forming an orifice with a separate plate is advantageous for shortening the overall length, which is a requirement of the orifice, but attempts to share a vane pump or an internal gear pump with the body. In this case, it is impossible to manage the vane or the clearances on both sides of the inner and outer rotors of several tens of microns because there is a possibility that the undulation and deformation of the plane may occur.
In addition, as described in Patent Document 2, when an orifice is drilled in an oblique wall formed by casting in the middle of a feedback circuit, drill rigidity is required because a small hole is an oblique machining with respect to a preferred orifice. For this reason, it is difficult to machine a small hole, or the man-hour for setting an oblique machining position is increased, and further, the length of the orifice is increased.
Furthermore, as described in Patent Document 3, if the processing for closing the throwing hole is performed while the orifice length is shortened by processing up to the front of the orifice, the processing man-hours and dimensional control man-hours increase, which is disadvantageous in terms of cost. It is.

Shokai 63-101355 Japanese Patent No. 4244346 Japanese Patent No. 4129115

  The present invention has been made to solve the above-mentioned problems, and can reduce oil pressure pulsation from an oil pump, stably supply control oil pressure to an actuator, and further provide a separate oil pump and control valve. It is to provide a hydraulic control device that integrates necessary functions in a divided body.

In order to solve the above-mentioned problem, in the invention according to claim 1, a pressure reducing valve that decompresses the pressure oil discharged from the oil pump and discharges excess oil to the suction area space or outside, and moves to the housing A spool that is freely mounted and has a different outer diameter, and a spring member that is fitted into the housing and engages the tip of the spool,
Since the portion where the outer diameter of the spool is different is connected to the line pressure circuit and the pressure acts on the large-diameter side of the spool, the load is larger than the small-diameter side of the spool. The pressure reducing valve that moves and opens the corner portion of the intermediate portion of the spool so that the pressure oil is discharged to the suction area space or outside and the pressure is kept constant, and the pressure reducing valve is accommodated and the spool A housing having a feedback chamber in which portions having different outer diameters are connected to a line pressure circuit, and a cover having a cover oil passage that is mounted on the housing and communicates with a housing oil passage formed in the housing. In the control device,
The feedback circuit connected from the oil pump to the feedback chamber is formed with at least one weir in the feedback circuit that coincides with the mating surface of the opposite cover or housing, and is positioned on the upper surface of the weir to restrict the circulation function. The groove | channel which makes | forms is formed, It is characterized by the above-mentioned.

According to the present invention, the pressure oil including the pulsation from the oil pump that circulates in the feedback circuit is attenuated by the groove formed on the mating surface side of the weir formed in the circuit to constitute the pressure reducing valve. The spool enters the feedback chamber between the large and small diameters of the spool, overcomes the elastic force of the spring member with a small hydraulic pulsation and stable pressure, and the spool moves.
As a result, the area opened to the suction area space is kept substantially constant, and the excess oil is discharged almost uniformly, so that the regulated pressure is stable with little hydraulic pulsation including the discharge pressure from the oil pump. It becomes line pressure.
The groove may be on the upper surface of the weir, or the upper surface of the weir may be substantially flush with the mating surface, and only the groove may be processed on the opposite plane side.
Moreover, since the pressure oil discharged from the oil pump passes through the groove shape provided on the upper surface of the multiple weirs formed in the feedback circuit, it can be formed at low cost by easy processing such as end mill, and the number is increased. Therefore, even if the groove is large, the hydraulic pulsation is attenuated without clogging with foreign matters, and the life of the hydraulic component can be extended.

According to a second aspect of the present invention, the housing has a substantially circular pocket, and a suction area space is formed in a region where the clearance increases by engaging with the rotation shaft and rotationally driven. An oil pump that is rotatably accommodated in which a discharge area space is formed in a decreasing area, and pressure oil that has been regulated by the pressure reducing valve are introduced, and pressure oil that is regulated toward the downstream actuator is introduced. And a solenoid valve that can be controlled from substantially zero to a maximum pressure.
According to the present invention, an oil pump and a solenoid valve are additionally provided in a housing having a pressure reducing valve having a spool structure, so that the clearance of the pump sandwiched between the housing and the cover can be accurately managed. In addition, the pressure oil discharged from the oil pump flows directly into the pressure reducing valve through the hydraulic circuit inside the housing which is the same housing, and the pressure oil made excessive by the pressure reducing valve is short in the suction area space of the oil pump directly. It will be returned in the circuit. Also, the pressure oil regulated by the pressure reducing valve is supplied to the solenoid valve by the hydraulic circuit in the housing, and the pressure oil corresponding to the required pressure is adjusted from the solenoid valve output port to the actuator in accordance with the control of the solenoid valve. Can be sent freely.
Furthermore, since the present invention is provided with an oil pump added to the housing, the hydraulic circuit is shortened and downsized, and the side clearance of the oil pump for vanes and external gears can be maintained with high accuracy, and the volume efficiency A small hydraulic control device having a high oil pump can be realized.

According to a third aspect of the present invention, the oil pump is capable of normal rotation and reverse rotation, and has a one-way valve opening function for communicating the pressure oil generated in the suction area space during the reverse rotation to the discharge area space. A stop valve and a safety valve provided on the same oil path as the pressure reducing valve that opens at a pressure higher than the pressure regulated by the pressure reducing valve are provided .
According to the present invention, the oil pump eliminates the restriction between forward rotation and reverse rotation, and does not suck in excess pressure oil from the normal discharge side circuit even when the oil pump operates in reverse with respect to the normal forward rotation. The discharge to the suction side can be immediately returned to the discharge area space through the check valve. Of course, since it is a check valve, it does not open even when the pressure increases during normal forward rotation, and the discharged pressure oil does not serve its purpose and is not returned to the suction area space. Since the check valve and the safety valve are provided, the check valve does not necessarily require an engine output shaft limited to rotation in one direction as a power source, and other rotation shafts, for example, a rotation shaft for traveling transmission, are not required. This can be used as an input, increasing the degree of freedom of layout. Moreover, according to the safety valve, safety can be improved even if the pressure reducing valve malfunctions.

According to a fourth aspect of the present invention, the feedback circuit has grooves having a depth of 1 mm or less, a width of 1 mm or less, and a length of 2 mm or less, formed in three locations on the same axis in series, and between these grooves. Two weirs are formed on the surface.
According to the present invention, the groove for attenuating the hydraulic pulsation effectively functions as an orifice that is narrowed down with respect to the cross-sectional area of the feedback circuit, and the length of one groove is 2 mm or less, and the sum of the three orifices. By functioning, the hydraulic pulsation is attenuated efficiently.
In addition, by providing two weirs, the number of parts that function as orifices becomes three in succession, the combined orifice diameter becomes smaller, and each groove is relatively deep and wide so that foreign matter is not clogged. The width can be set, and processing by a ball end mill or the like can be facilitated.
Furthermore, since the groove shape is 1 mm or less in depth, 1 mm or less in width, and 2 mm or less in length, it is easy to process and avoids clogging of foreign matters, and can effectively reduce hydraulic pulsation from low temperature to high temperature. In addition, fatigue of hydraulic parts is further suppressed, and a long life can be realized.

  The present invention reduces the hydraulic pulsation discharged from the oil pump, stabilizes the hydraulic pressure to the actuator, and is provided in a body in which the oil pump and the hydraulic control part are divided, so that necessary functions can be consolidated in a small size.

Hereinafter, preferred embodiments of the hydraulic control apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic side view of a hydraulic control apparatus 10 showing an embodiment of the present invention.
FIG. 2 is a perspective view showing an overview of the cover 20 viewed from the outside when attached to a case (not shown). Figure 3 is a perspective view showing an overview of the housing portion 30 as viewed from the rear side corresponding to the case interior side for Figure 2.
4 and 5 are perspective views of the cover portion 20 and the housing portion 30 in which the mating surfaces of the cover portion 20 and the housing portion 30 are separated from each other.

2 and 3, the aluminum die-cast cover 21 is attached to a transaxle case (not shown) composed of a gear train (not shown), so that the outer periphery forms the same unevenness on the case and is flat. It has a matching surface 21a and is formed so that hydraulic oil in the case, that is, ATF, does not leak by sandwiching a gasket or the like (not shown).
Part of the mating surface 21a (see FIG. 3) is formed with a suction hole 21b for sucking ATF stored in an oil sump at the bottom of the case, and passes through a suction passage 21c of the cover 21 to be described later. It is connected to a suction port (not shown) located below 48. The suction passage 21c is drilled in a direction substantially orthogonal to the mating surface 21a, and a plug 23 is driven in to close the opening after processing.

The case and the hydraulic control device 10 are fixed by inserting bolts (not shown) into the bolt holes 22b that are substantially evenly arranged and tightening the female screw on the case side. The cover 21 is provided with a plurality of check ports 25 (see FIG. 2) for detecting a line pressure and a control pressure, which will be described later .
A check port plug 26 for closing the check port 25 is attached. Further, above the cover 21, a connector 24 that supplies a command current from the vehicle side to a later-described electromagnetic proportional valve (solenoid valve) 42 mounted on the housing 31 is inserted into a hole 42 a (see FIG. 4) that penetrates the cover 21. It is attached with a ring. Around the connector 24, a protective rib 22c is provided to prevent damage caused by stepping stones when the vehicle is running.

The configuration of the cover 21 on the case mounting side will be described with reference to FIG.
The cover 21 and the housing 31 are fixed by a plurality of housing fixing bolts 51, and a circular fitting portion 31a for positioning with the case is formed at the approximate center of the housing 31. A shaft insertion hole 31b for inserting a rotation shaft (not shown) to be input is formed inside the fitting portion 31a, and a shaft fitting portion 49a of an oil pump, which will be described later, is formed behind the shaft insertion hole 31b. It is positioned and can rotate by receiving the rotation of the rotating shaft in the shape of a two-sided width. A hole (not shown) is machined vertically in the center of the shaft insertion hole 31b in the axial direction, and the lower part is the diameter of an oil passage connected to a clutch (actuator) (not shown ) provided on the rotating shaft. It is opposed to a directional hole (not shown), and the upper part is connected to a control pressure port (not shown) of the electromagnetic proportional valve 42.
The electromagnetic proportional valve 42 is mounted on the upper side of the housing 31 in the lateral direction (left and right direction in FIGS. 3 and 5), and is fixed by a bracket 42b. Power supply to the electromagnetic proportional valve 42 is connected to an external power supply source by being connected to the connector 24 via the harness 43 and the harness connector 43a. A relief valve 46 (see FIG. 5), which will be described later, is provided inside the left side of the housing 31, and a relief discharge window 32f is provided for releasing ATF opened and discharged at a specified pressure.

Next, the internal structure of the cover part 20 and the housing part 30 is demonstrated using FIG.4 and FIG.5.
In FIG. 4, the cover 21 has a mating surface 22 d with the island-shaped housing 31 that is flush with the mating surface 21 a with the above-described case, and the mating surface 22 d with the island-shaped housing 31. In the center, the suction port 21e and the discharge port 21f of the oil pump 48 are formed as grooves having a concave cross section by casting. The suction port 21e is formed integrally with a suction chamber chamber 21d provided below, and is connected to a suction hole 21b that opens to the mating surface 21a via a suction passage 21c.
On the other hand, the discharge port 21f is connected to a line pressure circuit A21g (cover oil passage) and a line pressure circuit B21h (cover oil passage) formed in the cover 21 in a groove having a concave cross section. The line pressure circuit A21g is connected to a regulator valve 44 that partially overlaps the line pressure circuit A34a (housing oil passage) formed in the housing 31 to form a pressure reducing valve. The line pressure circuit B21h communicates with a relief valve 46 that partially overlaps the line pressure circuit B34b (housing oil passage) formed in the housing 31 and functions as a safety valve.

  The reason why the mating surface 22d with the housing 31 has an island shape is that the cross-sectional area of the circuit can be increased in order to suppress the flow velocity of the suction port 21e and each hydraulic circuit. Since the thickness is unnecessary, it is formed thin to reduce the weight. A connector 24 for energizing the outside is provided at the top of the cover 21, and an O-ring is provided so that no oil leaks even if the inside of the case (not shown) is immersed in the ATF up to the height of the electromagnetic proportional valve 42. It is fixed with a bolt (not shown).

As shown in FIG. 5, the housing 31 which is a main part of the housing part 30 is molded by aluminum die casting in the same manner as the cover 21, and contacts the mating surface 22 d (see FIG. 4) of the cover 21 at the mating surface 32 c. These are fixed by the plurality of housing fixing bolts 51 described above.
A rotor pocket 32h for accommodating the oil pump 48 is bored in the center portion of the mating surface 32c of the milled housing 31, and the outer toothed inner rotor 49 constituting the oil pump 48 is concentric with the rotating shaft. The inner outer rotor 50 is disposed around the position where it is eccentric from the center of the rotation axis. The rotor pocket 32h is processed to have an inner diameter with a clearance of about 100 to 150 μm in diameter from the outer periphery of the outer rotor 50, and the depth is processed to be several tens of microns deeper than the thickness of the rotors 49 and 50.
The oil pump having the function described in the present invention is preferably an internal gear pump or a vane pump.

Furthermore, the structure of each valve will be described according to the flow of ATF (not shown) discharged from the oil pump 48 with reference to FIGS.
One of the ATF discharged from the oil pump 48 flows through the line pressure circuit A21g on the cover 21 side, and at the end thereof, moves to the line pressure circuit A34a on the housing 31 side, and around the spool 44a of the regulator valve (pressure reducing valve) 44 To flow.
Further, the ATF flows through the feedback circuit 39 according to the present invention and reaches the feedback chamber 36 where the portions having different outer diameters of the spool 44a are located. In the feedback chamber 36, since the outer diameter of the spool 44a is different between the large diameter and the small diameter, when pressure is applied, the load pushing the large diameter side becomes larger than the small diameter side, and the spool 44a moves toward the left side in FIGS. To do.

  On the side where the spool 44a moves, a spring member 44b (see FIG. 6) for pressing the spool 44a against the right side of FIGS. 5 and 6 in a state where no pressure is generated is provided. Counteracts the movement of the spool 44a due to pressure. At this time, the spool 44a is balanced at a position where the elastic force of the spring member 44b and the load due to the feedback pressure are balanced, and the corner portion of the intermediate portion of the spool 44a is opened by the V notch 35, thereby adjacent housings. ATF flows into the suction chamber chamber 31d of 31 and the pressure is kept constant. The other end of the spring member 44b is supported by the plate 44c.

The other ATF discharged from the oil pump 48 flows through the line pressure circuit B21h on the cover 21 side and moves to the line pressure circuit 34b on the overlapping housing 31 side, and the downward flow flows between the ball 46a seating the circuit and the ball It flows toward a relief valve (safety valve) 46 composed of a spring member 46b that presses down and a plate 46c that serves as a seat for the spring member 46b.
In addition, since the structure of the relief valve 46 is well-known, detailed illustration description is abbreviate | omitted.
On the other hand, an upward flow, flow into the supply pressure port of the solenoid proportional valve 42, the interior of the plunger is moved by the suction force of the electromagnetic portion when the electromagnetic proportional valve 42 receives a command current, the spool of the electromagnetic proportional valve 42 is in contact with it The supply pressure port and the control pressure port move to communicate with each other, and flow to a clutch (actuator) ( not shown ) through a hole formed in the center of the rotating shaft. The proportional solenoid valve 42 regulator valve (pressure reducing valve) 44 and similarly feedback circuit 32g is equipped, are assisted by a pressure operation of the internal spool of the solenoid proportional valve 42.
In addition, since the structure of the electromagnetic proportional valve 42 is well-known, illustration is abbreviate | omitted.

Next, a one-way valve 45 (see FIG. 5) that functions as a check valve provided above the regulator valve 44 will be described.
Since the oil pump 48 is driven by a rotation shaft that is synchronized with a tire traveling shaft (not shown), the oil pump 48 rotates in the reverse direction when the vehicle moves backward. As a result, a reverse flow is generated in which ATF is sucked from the discharge port 21f and discharged to the suction port 21e. In this case, the discharge side that does not have sufficient ATF is negatively pressurized and the suction side is temporarily pressurized, so that the circuit is not established.
In order to avoid this, a seat surface (not shown) provided inside the housing 31, a ball (not shown), a spring member 45a, a plug (not shown) for closing the circuit, and a retaining plate 45c The one-way valve 45 comprised by these functions.
In this case, normally, when the line pressure is generated, the ball closes the holding spring member 45a and the one-way communication path 32e connected to the suction side by pressing the line pressure.
On the other hand, when the oil pump 48 reverses and ATF flows into the suction port 21e, the ball is pressed by overcoming the resilience of the spring member 45a through the one-way communication path 32e and flows into the line pressure circuit A34a. The ATF that has flowed into the line pressure circuit A34a is again sucked into the discharge port 21f, and this flow is repeated. Note that the spring member 45a of the one-way valve 45 has a small elastic force so as to open at several kilopas.

Next, the structure of the feedback circuit 39 for suppressing hydraulic pulsation will be described with reference to FIGS. 6 and 7 and FIG.
The feedback circuit 39 that communicates with the feedback chamber 36 of the regulator valve 44 has a plurality of, for example, three weirs 39a in which the upper surfaces of the mating surface 21a of the cover 21 and the mating surface 32c of the housing 31 coincide with each other on substantially the same axis. Is provided.
The weir 39a is formed by die casting, and the length in the circuit direction, in other words, the thickness of the weir 39a is secured to ensure strength, so that the bottom is about 3 mm, and the slope is 1 to 2 mm at the mating surface 32c. Is provided. An orifice groove 39b is formed by ball end milling along the flow direction of the feedback circuit 39 in each of the upper surfaces of the weirs 39a, in other words, the mating surfaces 32c of the housing 31 mated with the mating surfaces 21a of the cover 21. As shown in FIG. 7, the cross-sectional shape has a width s, a depth h, and corners forming a radius r in accordance with the tip shape of the ball end mill.
The cross-sectional area of the orifice groove 39b is significantly smaller than the cross-sectional area W × H of the feedback circuit 39, and the width s is set to about 1 mm and the depth is set to about 0.5 mm so that it is easy to process and does not clog foreign matter. Yes. The three orifice grooves 39b are continuous, so that the combined orifice equivalent diameter is about φ0.5 mm that effectively suppresses hydraulic pulsation, and the orifice function can be realized without drilling.
When the length is 2 mm, there is a definition of choke compared to the equivalent of the orifice diameter, which is the cross-sectional area of the groove, but when it is about 2 mm, the result is equivalent to the attenuation of hydraulic pulsation at minus temperature. As a result, the inventor determined that it was effective.
The groove may be on the upper surface of the weir, or the upper surface of the weir may be substantially flush with the mating surface, and only the groove may be processed on the plane side of the opposed cover 21.

At the beginning of development shown in FIG. 8, weirs 220 are provided at both end portions where the depth of the feedback circuit 39 changes, and an orifice 221 that is obliquely drilled is employed. However, the hydraulic pulsation has not been reduced, the processing time is long, and even with a φ0.8 mm drill, problems such as breakage have been presented. In the case of the orifice groove 39b of the present embodiment, even if it is a ball end mill with a width of 0.8 mm, since the machining depth is shallow, the length of the machining tip can be shortened, and the rigidity of the blade can be increased. Damage prevention is also easier.

Further, another embodiment for reducing hydraulic pulsation will be described with reference to FIG.
A drain chamber 37 for discharging ATF leaking from the outer periphery is provided at the back (not shown) of the hole into which the spool 44a is inserted. If the ATF in the drain chamber 37 is confined, the movement of the spool 44a is significantly slowed, which hinders the regulation of the line pressure. However, the spool 44a is restricted by restricting the inflow / outflow of the ATF in the drain chamber 37. It is also possible to suppress vibrations.
For this reason, in the present embodiment, the orifice groove 38 is provided so as to be directed outward from the housing 31 so as to be connected from the drain chamber 37 to the outside of the hydraulic control device 10 inside the case. The length of the orifice groove 38 is made long until it passes through the outer space (outside of the housing 31), but the surface overlapped with the cover 21 is formed at a position indicated by a broken line in FIG. doing.

The hydraulic control apparatus 10 according to the embodiment of the present invention is basically configured as described above, and operational effects will be described.
The pressure pulsation of the ATF flowing through the feedback circuit 39, that is, the pulsation of the oil pump 48 passes through the plurality of orifice grooves 38, so that the pressure significantly protruding from the line pressure is lowered stepwise. Since the feedback chamber 36 is a closed space and does not flow, the pressure state of the feedback chamber 36 is stable with no pulsation in a state where the average pressure on the upstream side and the downstream side of the feedback circuit 39 is not greatly different. .

Due to the stable pressure in the feedback chamber 36, the spool 44a is balanced at a position where the elastic force of the spring member 44b and the load due to the feedback pressure are balanced, and the corner of the intermediate portion of the spool 44a is constant at the V notch 35. Open to opening. Therefore, the amount of ATF flowing into the suction chamber chamber 32d of the adjacent housing 31 becomes substantially constant, and the line pressure is kept constant by stabilizing the oil amount balance.

According to the hydraulic control apparatus 10 according to the present embodiment described above, hydraulic pulsation can be effectively reduced, and stabilization and durability of hydraulic control are increased.
In addition, a small oil pump with a small number of teeth can be combined with other valves to form a single body, and a hydraulic control device can be realized in a small size at low cost.
Furthermore, since the rotational direction is not limited, the degree of freedom of the input method is increased, and it can be applied to various hydraulic devices.

The orifice groove 39b of the feedback circuit 39 and the orifice groove 38 of the drain chamber 37 of the spool 44a described in the present embodiment have been described as being provided in the housing 31, but the cover 21 fitted to the housing 31 has been described. There is no problem even if it is located in the circuit on the side. That is, it is needless to say that there is no difference from the present invention as long as only the weir is formed and the groove is processed on the mating side so as to function as an orifice groove when superimposed.

  Furthermore, in order to make the orifice groove as short as possible, it is possible to end mill the die-casting weir and its mating part to shorten the orifice groove part that serves as a drawing function. If there is a cutting tool by this processing, since the processing time is short, there is no significant cost increase, and more effective removal of hydraulic pulsation is possible.

1 is a schematic side view of a hydraulic control apparatus 10 showing an embodiment of the present invention. It is a perspective view which shows the general appearance of the cover part 20 visible from the outside, when attached to a case (not shown). FIG. 3 is a perspective view showing an overview of a housing portion 30 as viewed from the inside of the case, which is the back side of FIG. 2. FIG. 3 is a perspective view of the hydraulic control device 10 as viewed from the cover unit 20 side. FIG. 3 is a perspective view of the hydraulic control device 10 as viewed from the housing part 30 side. It is a schematic diagram of a feedback circuit. It is sectional drawing of the VII-VII line of FIG. It is an enlarged view of the conventional feedback circuit of a hydraulic control apparatus.

DESCRIPTION OF SYMBOLS 10 Hydraulic control apparatus 20 Cover part 21 Cover 21a, 21m Mating surface 30 Housing part 31 Housing 32c Mating surface 32e One-way communication path 38 Orifice groove 39 Feedback circuit 39a Weir 39b Orifice groove 42 Electromagnetic proportional valve 44 Regulator valve (pressure reducing valve)
44a Spool 45 One-way valve (check valve)
46 Relief valve (safety valve) 48 Oil pump

Claims (4)

A pressure reducing valve that depressurizes the pressure oil discharged from the oil pump and discharges excess oil to the suction area space or to the outside. The pressure reducing valve is movably mounted on the housing and is inserted into the housing. And a spring member engaged with the tip of the spool,
Since the portion where the outer diameter of the spool is different is connected to the line pressure circuit and the pressure acts on the large-diameter side of the spool, the load is larger than the small-diameter side of the spool. The pressure reducing valve that moves and opens the corner portion of the intermediate portion of the spool so that the pressure oil is discharged to the suction area space or outside and the pressure is kept constant, and the pressure reducing valve is accommodated and the spool A housing having a feedback chamber in which portions having different outer diameters are connected to a line pressure circuit, and a cover having a cover oil passage that is mounted on the housing and communicates with a housing oil passage formed in the housing. In the control device,
The feedback circuit connected from the oil pump to the feedback chamber is formed with at least one weir in the feedback circuit that coincides with the mating surface of the opposite cover or housing, and is positioned on the upper surface of the weir to restrict the circulation function. A hydraulic control device characterized in that a groove is formed.   The hydraulic control device according to claim 1, wherein a substantially circular pocket is formed in the housing, and a suction area space is formed in a region where a clearance is increased by engaging and rotating the rotation shaft. The oil pump accommodated in a rotatable manner in which a discharge area space is formed in the area where the gap is reduced, and the pressure oil pressure-adjusted by the pressure-reducing valve are introduced, and the pressure is regulated toward the actuator on the downstream side. And a solenoid valve capable of controlling oil from substantially zero to a maximum pressure.   3. The hydraulic control apparatus according to claim 2, wherein the oil pump is capable of normal rotation and reverse rotation, and has a one-way valve opening function for communicating pressure oil generated in the suction area space during the reverse rotation to the discharge area space. A hydraulic control device comprising: a check valve having a safety valve provided on the same oil passage as the pressure reducing valve that opens at a pressure equal to or higher than the pressure regulated by the pressure reducing valve. 2. The hydraulic control device according to claim 1, wherein the feedback circuit has grooves each having a depth of 1 mm or less, a width of 1 mm or less, and a length of 2 mm or less, and is formed in three locations on the same axis in series. A hydraulic control device having two weirs formed between them.

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