JPS6283558A - Damper device of gear train - Google Patents

Abstract

PURPOSE:To stabilize a damper effect through stabilization of operation of a check valve, by a method wherein a check valve situated to the hydraulic circuit of the hydraulic damper mechanism of a gear train, driving the cam shaft of an internal combustion engine, is situated in a position where a centrifugal force is ineffective. CONSTITUTION:A damper mechanism A operated by means of the oil pressure of a gear train is positioned to a flange member 13 secured to a large part 7a of a cam shaft 7. An oil pressure introduced in the damper mechanism A is fed from an oil pressure source through an axis hole 7c of a cam shaft 7. A check valve 19, adapted to prevent the occurrence of reverse flow of pressure oil, is placed so that a valve body is operated within an axis hole 7c and besides in the axial direction of the cam shaft 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a damper device that prevents the occurrence of resonance in a gear train that drives something with large torque fluctuations, such as a camshaft of an internal combustion engine.

(Prior art and its problems) Generally, in a gear train that drives something with large torque fluctuations such as a camshaft, gear backlash,
Due to the backlash of the bearing or the complex relationship between the rigidity and inertial mass of each component, resonance may occur at a certain rotation point, and when such resonance occurs, drive noise increases and may even lead to destruction. There is also.

For this reason, as a damper device for a gear train that prevents the occurrence of resonance, conventionally, a damper device is installed between a shaft and a gear rotatably fitted to the shaft, with the axis oriented in a direction approximately perpendicular to the radial direction of the gear. It was constructed by providing a plurality of coil springs at equal intervals in the circumferential direction.

Therefore, the magnitude of the damper effect is determined only by the spring load, so when increasing the damper effect, the spring diameter must be increased, and the spring may become stiff over time, making it difficult to obtain a stable damper effect over a long period of time. The problem was that I couldn't do it.

Therefore, if the elastic force of the damper mechanism is applied by hydraulic pressure, a high damper effect can be obtained without increasing the diameter, and a sustainable damper effect can be obtained over a long period of time. However, in such a hydraulic damper mechanism,
A check valve that prevents the backflow of pressure oil from a pressure oil supply source such as an oil pump is installed inside a rotating gear or shaft, so centrifugal force prevents the check valve from operating. It becomes stable, and the damper effect becomes unstable.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is possible to obtain a stable damper effect by preventing the operation of a check valve connected to a pressure oil supply source from being affected by centrifugal force. The purpose of the present invention is to provide a damper device for a gear train that enables the following.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a damper mechanism that prevents resonance from occurring between a shaft and a gear rotatably fitted to the shaft. In the damper device for the gear train, the elastic force of the damper mechanism is applied by hydraulic pressure, and pressurized oil is supplied to the damper mechanism through the axial hole of the shaft, and the damper mechanism is configured to apply pressure to the damper mechanism through the axial hole of the shaft. A check valve that operates in the axial direction of the shaft is provided.

(Operation) Since the operation of the check valve that adjusts the hydraulic pressure, which is the source of the elastic force of the damper mechanism, is not affected by the centrifugal force caused by the rotation of the shaft, a stable damper effect can be obtained.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Fig. 1 is a partially cutaway front view of a gear train for driving a camshaft equipped with the damper device of the present invention, and Fig. 2 is a side view of the same. consists of a V-shaped cylinder block 3 having a pair of left and right cylinders 2 at the front and rear, a crankcase 4 below it, a pair of front and rear cylinder heads 5 above it, and each head cover 6 above it. ing.

The engine main body 1 is provided with a pair of front and rear camshafts 7 located in each of the head covers 6 in the upper part thereof, and also provided with a crankshaft 8 in the crankcase 4, and a drive gear 9 of the crankshaft 8. The driven gears 10 of each of the camshafts 7 are connected to each other via a gear train 11 consisting of at least two upper and lower idle gears 11a and 11b that mesh with each other. The rotation of the crankshaft 8 rotationally drives the camshaft 7 through a gear train 12 including a drive gear 9, a gear train 11, and a driven gear 10.

A damper mechanism A of the present invention is provided between the camshaft 7 and the driven gear 10 to prevent resonance from occurring.

That is, a flange member 13 is fixed to the large diameter portion 7a of the camshaft 7 so as to be immovable in both the circumferential direction and the axial direction. At the upper part of the flange member 13, a third
5 and 6, a cylinder member 14 is provided with its axis oriented perpendicularly to the radial direction of the driven gear 10. As shown in FIGS. The cylinder member 14 has one end surface open and the other end surface closed with a cap 15. A plunger 16 is fitted inside the cylinder member 14 so as to be freely protrusive and retractable from the opening on the one end surface, and the plunger 16 is pushed in the projecting direction by a coil spring 17. Being pressed. As shown in FIGS. 3 and 4, the cylinder members 14 are fitted onto the large-diameter portion 7a of the camshaft 7 so that they can be moved individually in the circumferential direction but cannot be moved in the axial direction, so that they are overlapped with each other. Fitting holes 1 are provided correspondingly to the driven gear 10 and the Serashi gear 18, respectively.
0a, 18a, and the tip end surface of the plunger 16 is abutted and engaged with an arcuate engagement surface 10b at one end edge of the fitting hole 10a of the driven gear 10.

Inside the cylinder member 14, there is a communication hole 13a formed in the flange member 13, a communication hole 7b formed in the camshaft 7, and a reverse hole provided at the inner end of the axial center hole 7C of the camshaft 7. It communicates with the shaft hole 7C via a stop valve 19. The check valve 19 consists of a casing 19C having an inlet 19a and an outlet 19b, a ball valve body 19d that opens and closes the inlet 19a, and a spring 19e that presses the valve body 19d in the valve closing direction. 19b communicates with the communication hole 7b of the camshaft 7. The camshaft 7
The outer end surface of the axial hole 7C is closed by a cap 20. The axial center hole 7C of the camshaft 7 includes a through hole 21 bored in the peripheral wall on one end side of the camshaft 7 along the radial direction, and an annular hole 7C carved in the outer peripheral surface of the camshaft 7 into which the through hole 21 opens. It communicates with a discharge port of a hydraulic pump (not shown) via the groove 22 and a passage 23a provided in the bearing portion 23.

Located between the driven gear 10 and the clutch gear 18 and displaced 180 degrees in the circumferential direction from the damper mechanism A, there is a clutch mechanism B for eliminating backlash between the driven gear 10 and the gear llb that meshes with the driven gear 10. is provided. The servicing mechanism B is arranged such that the flange member 13 is connected to the cylinder member 14 of the damper mechanism A by 180 degrees in the circumferential direction.
The cylinder member 24 has a cylinder member 24 which is displaced by a degree and whose axis is perpendicular to the radial direction of the driven gear 10, and a pair of plungers 25 are provided inside the cylinder member 24 so as to be freely retractable from openings on both end faces thereof. 26 are fitted, and these plungers 25 and 26 are each pressed in the projecting direction by a coil spring 27. The cylinder member 24
are fitted into the fitting holes toc, 18b, which are provided in correspondence with the driven gear 10 and the Serashi gear 18, respectively, and the tip surface of one plunger 25 is fitted in an arc-shaped engagement with one end edge of the fitting hole 18b of the Serashi gear 18. It is abuttingly engaged with the surface 18c. The tip end surface of the other plunger 26 is abutted and engaged with an arcuate engagement surface 10d at one end edge of the fitting hole 10c of the driven gear 10. The inside of the cylinder member 24 communicates with the axial center hole 7c of the camshaft 7 through a communication hole 13b formed in the flange member 13, a communication hole 7d formed in the camshaft 7, and the check valve 19. has been done.

Two damper springs 28a and 28b are provided on one side of the damper mechanism A and the release mechanism B, and one damper spring 28c and one release spring 29 are provided on the other side. It is being The damper springs 28a to 28c are the third damper springs 28a to 28c.
As shown in FIGS. 4 and 7, the driven gear 10
and the flange member 13 are fitted into fitting holes 10e and 13c which are provided in correspondence with each other. The damper springs 28a to 28c are arranged with their axes perpendicular to the radial direction of the driven gear 10, and have one end connected to one spring seat 30 and the other end connected to the other spring seat 3.
1 and are respectively abutted and locked.

These spring seats 30, 31 are arranged to span both the driven gear 10 and the flange member 13, respectively. Further, as shown in FIG. 3, FIG. 4, and FIG.
It is fitted into fitting holes 10f and 18d which are provided in correspondence with each other. The spring 29 is disposed with its axis perpendicular to the radial direction of the driven gear 10, and has one end in contact with one spring seat 32 and the other end in contact with the other spring seat 33. It has been stopped. These spring seats 32 and 33 are arranged astride both the driven gear 10 and the servo gear 18, respectively.

Next, the operation of the gear train damper device of the present invention having the above-described structure will be explained. Passage 23a, annular a22, through hole 2
1. Axial hole 7c, check valve 19, and communication holes 7b, 13a
Hydraulic pressure is introduced into each cylinder member 14.24 by sequentially valving the cylinder members 14.24. Therefore, the plunger 16 of the damper mechanism A is biased along the direction perpendicular to the radial direction of the driven gear 10 by the spring force of the spring 17 and the hydraulic pressure. Further, the plungers 25 and 26 of the activation mechanism B are also pressed along the direction perpendicular to the radial direction of the driven gear 10 by the spring force of the spring 27 and hydraulic pressure. Furthermore, damper springs 28a to 28C
The spring 29 is pressed in a direction perpendicular to the radial direction of the driven gear 10.

Therefore, the driven gear 10 and the flange member 13, that is, the camshaft 7 are connected to the damper mechanism A and the damper spring 28a.
The driven gear 10 and the activation gear 18 are urged to rotate in the relative direction by the elastic forces of the activation mechanism B and the activation spring 29.

When the camshaft 7 rotates through the gear train 12 in this state, two forces, the spring force of the spring 17 and the hydraulic pressure, act on the damper mechanism A, and the damper spring 28a
~28c, only the spring force acts to provide a damper effect, and even if sheet metal resonance occurs, the resonance is quickly extinguished by the damper effect.

In addition, two forces, the spring force of the spring 27 and the hydraulic pressure, act on the squeezing mechanism B, and only the spring force acts on the squeezing spring 29 to apply the squeezing force, so that it meshes with the driven gear 10. Backlash with idle gear llb is eliminated.

Note that damping in the forward rotation direction of the driven gear 10 is carried out by the damper mechanism A, and damping in the reverse rotation direction is carried out in the damper mechanism B, which has the advantage that only one check valve 19 is required. (In order to have the same damper mechanism in both forward and reverse directions, the cylinder member, plunger, and check valve should be installed separately for forward and reverse rotations.
(must be provided as a set).

Also, to explain the operation of the check valve 19 shown in FIG. The body 19d resists the biasing force of the spring 19e and the camshaft 7
, and opens the inlet 19a. On the other hand, although the camshaft 7 rotates, since the ball valve element 19d is on the axis of the camshaft 7, no centrifugal force is generated on the valve element 19d. Furthermore, since the ball valve element 19d operates in the axial direction of the camshaft 7, no component of centrifugal force is generated in the operating direction of the valve element 19d. Therefore,
The force acting on the ball valve body 19d in the operating direction is caused by the spring 19e.
Therefore, the valve opening pressure of the valve body 19d is prevented from fluctuating due to centrifugal force.

Note that it is also possible to replace the spring 29 in the above embodiment with a damper spring. Furthermore, the present invention is applicable not only to gear trains that drive the camshafts of the internal combustion engines described above, but also to a wide range of gear trains that drive engines that experience severe torque fluctuations. Further, the configuration and number of damper mechanisms A may be changed in various ways as long as the desired purpose can be achieved.

(Effects of the Invention) As described above, the gear train damper device of the present invention has a damper mechanism for preventing resonance between a shaft and a gear rotatably fitted to the shaft. In the damper device, the elastic force of the damper mechanism is applied by hydraulic pressure, and pressurized oil is supplied to the damper mechanism through the axial hole of the shaft, and the damper mechanism is provided with pressure oil in the axial direction of the shaft within the axial hole. Since the check valve is provided, a high damper effect can be obtained without increasing the diameter, and a sustained damper effect can be obtained over a long period of time. Furthermore, since the operation of the check valve is not affected by centrifugal force, it is possible to obtain a stable damper effect against rotation of the shaft.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a partially cutaway front view of a camshaft driving gear train equipped with the damper device of the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a portion of the damper device. 4 is a sectional view along the TV-IV line in FIG. 3, FIG. 5 is a side view of the flange member, FIG. 6 is a side view of the same, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 4. FIG. A... Damper mechanism, 7... Camshaft, 10...
・Driven gear, 19... Check valve, 19a... Inlet, 19b... Outlet, 19C... Casing, 19d
...Ball valve body, 19e...Spring. Applicant Honda Motor Co., Ltd. Agent Patent Attorney Satoshi Watanabe

Claims (1)

[Claims] 1. In a gear train damper device that includes a damper mechanism that prevents resonance between a shaft and a gear that is rotatably fitted to the shaft, the elastic force of the damper mechanism is applied using hydraulic pressure. Pressure oil is supplied to the damper mechanism through an axial hole of the shaft, and a check valve that operates in the axial direction of the shaft is disposed in the axial hole. Gear train damper device.