JPH0449385Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a clutch booster that is provided to reduce the pressing force on the clutch pedal during clutch operation, and in particular has a function to prevent sagging that may occur when starting a car. The present invention relates to a clutch booster equipped with a clutch booster.

[Prior Art] A recent clutch device is equipped with a pedal force reduction mechanism in its operation system to reduce the pedal force.

FIG. 3 shows a clutch device equipped with a clutch booster 1 that uses the vacuum force of the engine to boost the pedal effort.

In the diagram, 2 is the clutch, 3 is the transmission,
Reference numeral 4 denotes a release lever for disengaging and disengaging the clutch 2, and the release lever 4 is connected to a push rod 5 of the clutch booster 1. The inside of the booster chamber 6 is partitioned by a diaphragm 15 as shown in FIG. 2, one chamber 7 is connected to a vacuum tank 9, and the other chamber 8 is connected to a rubber hose 10,
It is connected to an air filter (not shown) via a relay valve 11. The relay valve 11 is connected to a master cylinder 1 connected to a clutch pedal 12.
3 and is hydraulically connected to the clutch pedal 1.
The relay valve 11 is actuated by the hydraulic pressure generated by pressing the button 2.

Here, the structure of the conventional clutch booster 1 is
A brief description will be given in the figure.

A power piston 16 urged leftward in the figure by a return spring 24 is fitted into the booster chamber 6, and a diaphragm 15 is provided between the power piston 16 and the booster chamber 6.
The inside of the booster chamber is airtightly partitioned into chambers 7 and 8 by the diaphragm 15. Align the center axis of the power piston 16 with the push rod 1.
7 is fixed, and the push rod 17 hermetically passes through a seal block 18, which will be described later, to connect the piston 1.
It is in contact with 9.

A cylinder block 20 is attached to the chamber 7 side of the booster chamber 6, and a cylinder chamber 21 is bored in the cylinder block 20 concentrically with the push rod 7, and a pilot cylinder is installed in the direction crossing the cylinder chamber 21. A chamber 22 is bored and both are communicated by a passage 23. The seal block 18 that partitions the chamber 7 and the cylinder chamber 8 is fitted into the cylinder chamber 21, and a piston 19 is slidably fitted into the cylinder chamber 21. The piston 1
A push rod 5 connected to the release lever 4 is in contact with the opposite side of the push rod 17 of the release lever 9 . Also, the booster chamber 6 of the cylinder chamber 21
A hydraulic line from the master cylinder 13 is connected to the side.

Above the pilot cylinder chamber 22 is the valve cover 2.
A valve chamber 26 covered by a valve 5 is formed, and the valve chamber 26 and the chamber 7 are communicated with each other by a passage 27. A small chamber 29 having a valve seat 28 is formed inside the valve cover 25, and the valve plate 30 can be tightly attached to and separated from the chamber 29. Further, a valve seat 31 is formed on the lower periphery of the valve cover 25 and can protrude toward the center.
1, the valve body 32 can be tightly attached to and separated from the valve body 32. The valve plate 30 and the valve body 32 are connected by a rod 33, and the lower end of the rod is connected to the pilot cylinder chamber 22.
The pilot piston 34 is slidably inserted into the pilot piston 34. Further, the valve plate 30 is urged by a spring 35 in a direction in which it comes into close contact with the valve seat 28, and the valve body 32 is urged in a direction away from the valve seat 31 by a valve spring 36.

As described above, the chamber 7 is connected to the vacuum tank 9, the small chamber 29 is connected to the air filter, the valve chamber 26 and the chamber 7 are communicated through the through hole 27, and the valve chamber 26 and the chamber 8 are connected to each other. are connected by a rubber hose 10.

In such a clutch device, when the clutch pedal 12 is depressed to disengage the clutch, pressure oil from the master cylinder 13 is sent into the cylinder chamber 21. This hydraulic pressure acts on the piston 19 and the pilot piston 34, and first the pilot piston 34 moves upward and pushes up the rod 33. Following the movement of the rod 33, the valve body 32 comes into close contact with the valve seat 31, and the valve plate 30 separates from the valve seat 28. By the operation of the valve body 32 and the valve plate 30, the chamber 8, which is in a vacuum state by communicating with the chamber 7 via the valve chamber 26 and the passage 27, is communicated with atmospheric pressure via an air filter. Atmosphere to chamber 8 is relay valve 1
1, the pressure balance between chambers 7 and 8 is broken, and power piston 16 moves to the right in the figure.
This movement of the power piston 16 is transmitted to the push rod 5 via the push rod 17 and the piston 19, and the hydraulic pressure from the master cylinder 13 is transmitted to the push rod 5 via the piston 19, and the push rod 5 moves to the right to release the release lever. 4 clockwise to disconnect clutch 2 (see Figure 3).

When the clutch pedal 12 is returned during the clutch engagement operation, the oil pressure in the cylinder chamber 21 decreases, and the pilot piston 34 first releases the spring 36 and the spring 3.
5 is lowered downward via the rod 33. The valve plate 30 is in close contact with the valve seat 28 to cut off communication between the chamber 8 and atmospheric pressure via the relay valve 11 and the air filter, and the valve body 32 is in close contact with the valve seat 3.
1 and restore the communication state between chambers 7 and 8. The air in chamber 8 is sucked into vacuum tank 9,
becomes a vacuum state. The power piston 16 moves to the left in the figure by the force of the return spring 24, returning to the state shown in FIG. 2, and the clutch 2 becomes engaged.

As described above, since the depression force on the clutch pedal 12 is boosted by the clutch booster 1 and transmitted to the release lever 4 of the clutch 2, the burden on the driver in operating the clutch is reduced.

[Problems to be solved by the invention] When a car starts, that is, immediately after the clutch engages, the so-called sway phenomenon, in which the car body violently rocks back and forth and up and down, may occur, and if this sway phenomenon is severe, the car may no longer be able to drive. I get used to it.
This is thought to be because the clutch engagement operation causes sudden torque and load fluctuations in the power transmission device after the clutch, which causes vibrations in various places.

One of the major causes of this sagging phenomenon is the above-mentioned pressure fluctuation of the working fluid of the clutch booster.

If the pressure of the working fluid in the clutch booster fluctuates, the output of the clutch booster will fluctuate, resulting in a fluctuation in torque transmission in the clutch. As a result, torque is not smoothly transmitted to the power transmission device after the clutch, resulting in a sagging phenomenon.

In view of the structure of the clutch booster 1 described above,
Relay valve 11 and chamber 8 are the causes of pressure fluctuations in the working fluid (air) inside the clutch booster.
There is a rubber hose 10 that connects the In chamber 8 of clutch booster 1, there is a pressure change between atmospheric pressure and vacuum pressure as the clutch engages and disconnects, and in the process of this pressure change, the rubber hose with low rigidity expands and contracts, amplifying the pressure change. It is being

In the past, measures have been taken to prevent this sagging phenomenon, but all of them are for areas other than the clutch booster. For example, vibrations generated at the rear wheel may be suppressed by providing a vibration absorbing material such as rubber in the middle of the connection between the master cylinder 13 and the release lever 4, or by increasing the diameter of the rear wheel shaft to increase its rigidity.

However, all of these measures were applied to areas other than the areas where the cause of the scabs occurred, and they did not eliminate the cause itself and could not be considered fundamental countermeasures.

In view of the above-mentioned circumstances, the present invention aims to improve the clutch booster itself and eliminate the cause of the clutch booster itself.

[Means for Solving the Problems] The present invention has a cylinder chamber to which pressure oil is supplied from a master cylinder that operates in conjunction with a clutch pedal, and a pilot cylinder chamber that communicates with the cylinder chamber. a cylinder block in which a piston connected to a release lever of a clutch is slidably fitted into the pilot cylinder chamber, and a pilot piston is slidably fitted in the pilot cylinder chamber; The interior is partitioned by a diaphragm into a chamber on the cylinder block side and a chamber on the anti-cylinder block side, and has a return spring that biases the diaphragm toward the chamber on the anti-cylinder block side. A vacuum tank is connected, and the tip of a push rod integrally attached to interlock with the diaphragm communicates with a booster chamber connected to the piston, a chamber on the cylinder block side of the booster chamber, and a chamber on the opposite side of the cylinder block. A valve chamber is formed inside the valve chamber and is connected to the pilot piston via a rod, so that the valve chamber is connected to the pilot piston through a rod, and the pilot piston is connected to the cylinder chamber during the clutch disengagement operation and when pressurized oil is supplied to the pilot cylinder chamber. Upon operation, the chamber on the opposite side of the cylinder block is isolated from the chamber on the cylinder block side, and the chamber on the opposite side of the cylinder block is communicated with atmospheric pressure via the valve chamber, and the cylinder is closed off when the clutch is engaged. With the operation of the pilot piston when pressure oil is not supplied to the valve chamber and the pilot cylinder chamber, the chamber on the side opposite to the cylinder block is made to communicate with the chamber on the cylinder block side via the valve chamber, and the chamber on the side opposite to the cylinder block is communicated with the chamber on the cylinder block side through the valve chamber. In a clutch booster equipped with a relay valve that shuts off atmospheric pressure, the chamber on the side opposite to the cylinder block and the valve chamber are connected via a damper, and the damper has a throttle hole so that when the clutch is disengaged, the chamber on the side opposite to the cylinder block is connected to the valve chamber. A float valve is provided, which is closed by the atmospheric pressure sucked into the chamber on the block side and the biasing force of a spring, and opens against the biasing force of the spring by exhausting the air in the chamber on the side opposite to the cylinder block when the clutch is engaged. It is characterized by:

[Operation] In a normal clutch engagement/disengagement operation, the float valve opens and closes according to the air flow, and air flows into and out of the chamber on the side opposite to the cylinder block. When pressure fluctuations occur in the airflow, the float valve is kept closed by the biasing force of the spring, and the air flows in and out through the throttle hole, and is throttled and attenuated in the process of flowing in and out, suppressing pressure fluctuations. Ru.

[Example] Embodiments of the present invention will be described below based on the drawings.

In addition, in FIG. 1, the same parts as those shown in FIG. 2 are given the same symbols.

A pipe 38 is screwed into the port 37 of the relay valve 11, a damper 39 is connected to the outer end of the pipe 38, and the damper 39 and the chamber 8 are connected by a rubber hose 10.

Here, the structure of the damper 39 will be explained. Holes 41 and 42 are formed in the side surface (may be the top surface) and the bottom surface of the casing 40, respectively.
The pipe 38 is connected to the bottom hole 42, and the rubber hose 10 is connected to the bottom hole 42. A valve seat 43 is fixed to the bottom inner surface, and a float valve 44 that can be brought into close contact with the valve seat 43 is provided. A throttle hole 45 of a required diameter is bored in the float valve 44 , and the float valve 44 is pressed against the valve seat 43 by a relief spring 46 . or,
A protrusion 47 is provided on the inner surface of the casing 40 to ensure the opening and closing of the float valve 44.

Next, the operation of the clutch booster 1 equipped with the damper 39 will be explained.

As mentioned above, in the clutch disengaging operation, the valve plate 3
0 is away from the valve seat 28, and the valve body 32 is in close contact with the valve seat 31. In this state, air flows from the air filter through the small chamber 29, the valve chamber 26, the damper 39, and the rubber hose 10, and flows into the chamber 8. During this air inflow, the air passes through the throttle hole 45 of the damper float valve 44,
Subjected to a squeezing effect.

Further, when the clutch operation is performed, the valve plate 30 comes into close contact with the valve seat 28 as shown in the figure, and the valve body 32 separates from the valve seat 31. At this time, the air in the chamber 8 is transferred to the rubber hose 10, the damper 39, the pipe 38,
It flows into the chamber 7 through the valve chamber 26 and the passage 27.

In this process, when the air passes through the damper 39, the airflow pushes up the float valve 44 as shown by the two-dot chain line and flows in a wide open state. Therefore, in this air flow direction, there is no throttling effect by the throttling hole 45, and the return movement of the power piston 16 (return movement of the clutch) is performed quickly.

The anti-scratch effect achieved by providing the damper 39 is as follows. That is, the rubber hose 10
When the hose expands and contracts due to changes in air pressure, the expansion and contraction of the hose appears as a thin, highly vibrating reciprocating flow of air. In this case, the air flow enters and leaves the throttle hole 45 without particularly opening or closing the float valve 44. Therefore,
The air flow is throttled by the throttle hole 45, and vibrations are attenuated by viscous resistance. This suppresses the pressure fluctuation of the working fluid within the clutch booster, which is a major cause of the sagging phenomenon.

Note that the damper mechanism described above is only one example, and the structure is not limited to this.

[Effects of the invention] As described above, the present invention eliminates the pressure fluctuations in the working fluid of the clutch booster, which is a major cause of the sagging phenomenon when starting a car, and is highly effective in preventing the sagging phenomenon. It has a simple structure and can be easily modified and added to existing vehicles.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a sectional view of a conventional clutch booster, and FIG. 3 is an overall view of a clutch device equipped with a clutch booster. 6 is a booster chamber, 7 and 8 are chambers, 11 is a relay valve, 15 is a diaphragm, 39 is a damper, 44 is a float valve, 45 is a throttle hole, and 46 is a relief spring.

Claims (1)

[Claims for Utility Model Registration] It has a cylinder chamber to which pressure oil is supplied from a master cylinder that is linked to the clutch pedal, and a pilot cylinder chamber that communicates with the cylinder chamber. a cylinder block in which a piston connected to a lever is slidably fitted, and a pilot piston is slidably fitted in the pilot cylinder chamber; It is partitioned into a chamber on the side of the cylinder block and a chamber on the side opposite to the cylinder block, and has a return spring that biases the diaphragm toward the chamber on the side opposite to the cylinder block, and a vacuum tank is connected to the chamber on the side of the cylinder block, A push rod tip integrally attached to interlock with the diaphragm is capable of communicating with a booster chamber connected to the piston, a chamber on the cylinder block side of the booster chamber, and a chamber on the opposite side of the cylinder block, and is connected to atmospheric pressure. A communicable valve chamber is formed inside and connected to the pilot piston via a rod, and the valve chamber is connected to the pilot piston through a rod. The chamber on the cylinder block side is isolated from the chamber on the cylinder block side, and the chamber on the opposite side of the cylinder block is communicated with atmospheric pressure through the valve chamber, and is also connected to the cylinder chamber and the pilot cylinder chamber during clutch engagement operation. A relay that communicates the chamber on the opposite side of the cylinder block with the chamber on the cylinder block side via the valve chamber and isolates the chamber on the opposite side of the cylinder block from atmospheric pressure when the pilot piston operates when no pressure oil is supplied. In a clutch booster equipped with a valve, the chamber on the side opposite to the cylinder block and the valve chamber are connected via a damper, and the damper has a throttle hole so that when the clutch is disengaged, air is sucked into the chamber on the side opposite to the cylinder block. The present invention is characterized in that a float valve is provided, which is closed by the atmospheric pressure and the biasing force of a spring, and which opens against the biasing force of the spring by discharging the air in the chamber on the side opposite to the cylinder block when the clutch is engaged. clutch booster.