JPH0442577Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field The present invention is a clutch release cylinder, in particular, a spring is housed in a hydraulic chamber defined between an end wall of the cylinder body and a piston, A clutch release cylinder is provided in which the tip of a piston rod connected to the piston is brought into contact with a clutch release member by the elastic force of the spring, and the retraction limit of the piston approaches the end wall as the clutch fading wears. This invention relates to the improvement of a device with a function to warn of the wear limit of clutch fading.

(2) Prior art As described above, when the tip of the piston rod of the clutch release cylinder is constantly brought into contact with the clutch release member by the elastic force of the spring, the driver obtains a constant operating feeling regardless of the state of wear of the clutch fading. However, the problem is that the wear of the clutch fading cannot be noticed.

Therefore, a clutch release cylinder has been developed that generates an alarm when the clutch phasing wears out a predetermined amount. Conventionally, this type of cylinder has fixed movable members such as a movable contact that lights up an alarm lamp, and fixed contacts such as a fixed contact. It is known that the piston and the cylinder body are each provided with a member (see Japanese Utility Model Application Publication No. 51-65142).

(3) Problems that the invention aims to solve However, in the conventional model, the movable and fixed members are exposed around the cylinder body, so it is easy for other objects to collide with these members, and the movable and fixed members are deformed due to the collision. If a positional shift occurs due to the same reason, there is a problem in that it is not possible to accurately warn the wear limit of the clutch fading. Furthermore, the exposed movable and stationary members are susceptible to corrosion, and as a result, contact failure may occur at the wear limit of the clutch fading.

An object of the present invention is to provide the clutch release cylinder that can solve the above problems.

B. Structure of the invention (1) Means for solving the problem The present invention accommodates a spring in a hydraulic chamber defined between the end wall of the cylinder body and the piston, and uses the elastic force of the spring to cause the piston to move. abut the tip of the piston rod connected to the clutch release member,
In a clutch release cylinder in which the retraction limit of the piston approaches the end wall due to wear of the clutch phasing, a protective cylinder enclosing a reed switch for activating an alarm is provided so that the contact opening/closing direction of the reed switch is aligned with the piston. A permanent magnet is attached to the piston so as to face the reed switch, and is attached to the holding hole of the end wall so as to be parallel to the sliding direction of the reed switch, and closes the reed switch at the wear limit of the clutch fading. Features.

(2) Effect With the above structure, the permanent magnet and reed switch are not exposed around the cylinder body, and therefore can be protected from collision with other objects and corrosion. Furthermore, since the contact opening/closing direction of the reed switch is parallel to the sliding direction of the piston, and thus the moving direction of the permanent magnet, and the permanent magnet faces the reed switch, the magnetic flux density of the permanent magnet in the reed switch can be reduced. This makes it possible to use a small permanent magnet and easily attach it to the piston, as well as to reliably close the reed switch.

In this way, a warning can be issued accurately and reliably at the wear limit of the clutch fading.

(3) Example In the drawing, the crankshaft 1 and the main shaft 2 of the transmission
A diaphragm spring type clutch 3 is interposed between the clutch 3 and the release collar 4 of the clutch 3. One end of a release hawk 6 as a clutch release member whose intermediate portion is supported on a swing fulcrum 5 engages with the release collar 4 of the clutch 3. A clutch release cylinder 7 is connected to the other end of the release hawk 6.

The clutch release cylinder 7 is constructed as follows. The cylinder body 8 has an end wall 9 at one end and an opening 10 at the other end, and a piston 11 is slidably fitted into the cylinder body 8.
A piston rod 12 connected to one end surface of the piston 11 passes through the opening 10 so that its tip faces the release fork 6, and there is a hydraulic pressure between the other end surface of the piston 11 and the inner surface of the end wall 9 of the cylinder body 8. Room 1
3 is defined. The hydraulic chamber 13 is connected to a master cylinder (not shown), and a coiled spring 14 is compressed in the hydraulic chamber 13, and the elastic force of the spring 14 causes the tip of the piston rod 12 to lightly contact the release fork 6. Therefore, the clutch 3 is not actuated by this contact force.

In the above configuration, when pressure oil is supplied from the master cylinder to the hydraulic chamber 13, the piston 11 advances to the right, the release fork 6 swings counterclockwise in the drawing, and the clutch 3 is thereby disconnected. The release hawk 6 swings clockwise in the drawing as the clutch fading wears, so the piston 1
1 approaches the end wall 9 of the cylinder body 8.

The clutch release cylinder 7 is equipped with the following clutch fading wear warning device. The device consists of a reed switch 17 connected to an electric circuit with a lamp 15 as an alarm and a power supply 16, and a permanent magnet 18 for closing the reed switch 17.

The reed switch 17 is enclosed in a synthetic resin protection tube 19, and the protection tube 19 is connected to the cylinder body 8.
It is mounted in a holding hole 20 formed in the end wall 9 of the holder so as to be perpendicular to its axis. The protection tube 19 is prevented from coming off by a flange 21 and a pair of elastic claws 22 that engage with both opening edges of the holding hole 20, respectively.

When the protective tube 19 is attached to the end wall 9 in this way,
The opening and closing directions of contacts a and b in reed switch 17 are parallel to the sliding direction of piston 11.

A recess 2 is provided on the surface of the piston 11 facing the reed switch.
3 is open, and a permanent magnet 18 is fitted into the recess 23 to close the reed switch 17 at the wear limit of clutch fading.

In the above configuration, as the clutch fading wears out, the piston 11 and therefore the permanent magnet 18
approaches the reed switch 17, and when the wear limit of clutch fading is reached, the permanent magnet 18 closes the reed switch 17, causing the lamp 15 to light up and informing the driver of the said wear limit.

In this case, the permanent magnet 18 and the reed switch 17 are housed in the cylinder body 8 and in the holding hole 20 of the end wall 9 via the protective tube 19, respectively.
can be protected from collision with other objects and corrosion. Further, the contact opening/closing direction of the reed switch 17 is the sliding direction of the piston 11, and therefore the permanent magnet 1
Since the permanent magnet 18 is parallel to the moving direction of the reed switch 8 and faces the reed switch 17, the magnetic flux density of the permanent magnet 18 in the reed switch 17 can be increased. By using the reed switch 17, it is possible to easily attach it to the piston 11 and to reliably close the reed switch 17.

C. Effects of the invention According to the invention, by arranging the alarm activation reed switch and the permanent magnet at the specific position and in a specific relationship, the wear limit of clutch fading can be accurately and reliably warned. I can do it. Further, since the highly hard permanent magnet does not slide on the inner circumferential surface of the cylinder body, wear of the cylinder body can be prevented and its durability can be improved.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional front view showing an embodiment of the present invention. 3... Clutch, 6... Relay hawk as clutch release member, 7... Clutch release cylinder, 8... Cylinder body, 9... End wall,
11... Piston, 12... Piston rod, 1
3... Hydraulic chamber, 14... Spring, 15... Lamp as alarm, 17... Reed switch, 18...
...Permanent magnet, 19...Protective tube, 20...Retaining hole.

Claims (1)

[Scope of utility model registration request] A spring is housed in a hydraulic chamber defined between the end wall of the cylinder body and the piston, and the elastic force of the spring causes the tip of the piston rod connected to the piston to come into contact with the clutch release member, thereby causing clutch fading. In a clutch release cylinder in which the retraction limit of the piston approaches the end wall due to wear, a protective cylinder enclosing a reed switch for activating an alarm is provided so that the opening/closing direction of the contact of the reed switch is the sliding direction of the piston. A clutch characterized in that a permanent magnet is attached to the piston opposite to the reed switch and is mounted in a holding hole in the end wall parallel to the reed switch and closes the reed switch at the wear limit of the clutch fading. release cylinder.