JPH02231250A - Return device of brake pedal - Google Patents

Abstract

PURPOSE:To reduce the stepping force of a brake pedal by installing a turning arm integrally with a cam and applying a springy force of a return spring onto the turning arm, in the constitution in which brake is released by pushing- spreading a pair of levers by the turn of the cam which is interlocked with the brake pedal. CONSTITUTION:When a brake pedal of a deadman brake is stepped ON, a cam 86 is turned through a link rod 94 and a pad shift lever 95, and levers 81 and 82 are pushing-spread against the springy force of a brake spring 84, and a pair of pads 811 and 821 which contact the both sides of a brake disc 99 are open-separated, and thus brake is released. In this cass, the basic edge part 31 of a turning arm 3 which turns integrally with a cam shaft 861 is connected with the cam shaft 861 having the cam 86 installed, and a return spring 1 is laid between the top edge part 32 of the turning arm 3 and the engaging pin 41 at the top edge of a bracket 4. When the cam 86 is turned, the turning arm 3 is turned, exceeding the top dead center against the tension force of the return spring 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention... A dead man brake (prior art) relates to a brake pedal return spring that can reduce the pressing force on the brake pedal in a dead man brake. Used in industrial vehicles such as reach-type forklifts. This type of brake device releases the brake when you step on the brake pedal, and applies the brake when you take your foot off the brake pedal. That is. The brake device, as shown in FIGS. 5 to 7, includes a brake section 8 and a brake pedal 9l that rotates the brake 8 via a rod 94, a link 93, and a bedanore rod 911. The brake part 8 has a base end part 81
3,823 and a pair of levers 81 and 82 rotatably pivoted to an axle pin 85. A brake spring 84 is provided at the tip of both levers and biases both levers 81 and 82 toward each other. A cam 86 is provided between the tips of both levers 81 and 82 and rotates in a direction that pushes both levers apart.
It depends. Also, on the inside of both levers 81 and 82, there are bands 811 and 821 that support the brake disc 99.
is provided. In the above brake equipment. Normally, the brake disc 99 is supported by the biasing force of the brake spring 84 via the levers 81 and 82. Playing cows. And when the vehicle is running,
When you press the brake pedal 9L. pedal rod 911,
The rod 94 is pushed forward via the link 93 and the return spring 92, and the pad shift lever 9
The camshaft 861 rotates via the shaft 5. Therefore,
The cam 86 rotates. Push apart the space between both levers 81 and 82. Therefore, the support of the brake disc 99 by the pads all, 821 is released, and the brake is released. The vehicle can now run. In addition. In the same figure. Reference numeral 71 is an adjuster screw for adjusting cam clearance, 71l is a stopper thereof, 83 is a board for supporting levers 81 and 82 on the vehicle body, 831 is a bracket that rotatably supports a camshaft 86l, and 84l is a brake spring attached. This is a shaft for force use. [Problem to be solved] However. For the conventional brakes mentioned above. There are the following problems. In other words, for the above brake (,). First, the braking force is determined by the reaction force J of the brake spring, and the stronger the reaction force J, the greater the braking force obtained, but on the other hand, the force on the brake pedal also increases. However, after depressing the brake pedal 91 and releasing the brake,
As shown in Figure 4, the spring 9 has an extra stroke.
The composite reaction force H of the reaction force J of 2 and the reaction force K of the brake spring 84 is expressed as the pedal force. In addition, the above allowance stroke is. This is a stroke to prevent dragging between the pad 811 and the brake disc 99. on the other hand. The brake force is. It is generally known that this can be increased by increasing the reaction force of the brake spring. but. After all, to increase the braking force. It is necessary to increase the pedal force (see Figure 4 above). As mentioned above, in conventional brakes, the composite reaction force H corresponding to the extra stroke after releasing the 8 brakes is added to the pedal effort as a wasted force. Therefore, the burden of pedal force on the driver when releasing the brake is large. The present invention was made in view of these conventional problems. The present invention aims to provide a brake pedal return device that can reduce the force required to press the brake pedal. [Means for solving the problem] The present invention. A pair of levers whose base ends are pivotably connected to each other. A board that supports both levers on the vehicle body, a pad provided on the inside of both levers to hold the brake disc,
A brake spring that urges the levers toward each other, a cam that is installed between the tips of the levers and rotates in a direction that pushes the levers apart, and a brake that connects the cams so that they do not rotate. This invention relates to a brake having a pedal. and. A rotating arm that rotates integrally with the above force is provided, and a return spring is stretched between the tip of the rotating arm and the base plate, and the cam is rotated by the brake pedal. The brake pedal return device is characterized in that the rotating arm is configured to rotate beyond top dead center against the tension of the return spring. In the present invention, II should also be noted. A rotating arm that rotates integrally with the cam is provided, and a return spring is stretched between the tip of the rotating arm and the base plate. The rotating arm is configured to rotate past the top dead center against the tension of the return spring when the cam is rotated by the brake pedal. Further, in the present invention, as shown in the prior art described above, the pedal rod is arranged between the pedal rod 911 and the rod 94. Spring 92 is not provided. [Operation] In the brake pedal return device according to the present invention, a return spring is stretched between the tip of the rotating arm and the base plate, so that when the cam is rotated by the brake pedal, At the same time, the rotating arm rotates, and its tip rotates past the top dead center against the biasing force of the return spring. After the vehicle reaches top dead center, the return spring generates a force in the direction of pressing the brake pedal. That is. As shown in Figure 3, which will be described later, the return spring has a Force E in the direction that reduces the pedal effort
works. Therefore. Even if the reaction force F of the brake spring occurs after the brake is released, the total reaction force G of both brake springs decreases as shown in the figure. Therefore, only a small pedal force is required after the brake is released. Additionally, the return spring works in the direction of returning the brake pedal to its original position when applying the brakes. (Effect) As above. According to the present invention, it is possible to provide a brake pedal return device that can reduce the pressing force on the brake pedal. Additionally, since the force required to press the brake pedal can be reduced, it is easier to adjust the speed of industrial vehicles such as forklifts. Also, the above return spring is attached to the brake body. Its mounting position is high. Therefore. Road dust on the return spring. Rainwater etc. splashes up,
This will not cause any negative effects. [Example] Regarding a brake pedal return device according to an example of the present invention. This will be explained using Figures 1 to 4. That is, the return device of this example is used as a dead man's brake attached to a reach type forklift as shown in Figs. 1 and 2. Camshaft 86 provided with cam 86
A base end 3l of a rotating arm 3 that rotates integrally with the base end 3l is connected to the base end 3l of the rotating arm 3, and the tip 32 of the rotating arm 3 and the substrate 8
There is a return spring l between the bracket 831 of 3.
It is made by hanging. Also. This return device is. When the cam 86 is rotated by the brake pedal (see reference numeral 9I in FIG. 5, the same applies hereinafter), the rotation arm 3 moves against the return spring l.
It is constructed so that it can rotate beyond top dead center against the tension of That is, the rotating arm 3 has its base end 3l coaxially fixed to the camshaft 861. The camshaft 861 is connected to the rond 94 via a pad shift lever 95. Also. A locking pin 5 is provided at the distal end 32 of the rotating arm 3, and one end 1 of the return spring l is attached to the locking pin 5.
Install l. The other end 12 of the return spring 1 is. Attach to the locking pin 41 of the bracket 4. Also. The bracket 4 is. Attach to the board 831 above. In addition, the levers 81 and 82 have a pair of pads 811 on the inside.
, 821, and the brake disc 99 is supported by both. Moreover, both the levers 81 and 82 are as follows. Base end portion 81
3,823 are pivotably connected to each other. It is attached to the board 83 that is supported on the vehicle body. Also, the tips of both the levers 81 and 82 are provided with. The brake spring 84 is biased in the direction in which both levers approach each other. Further, in the prior art, the spring 92 provided alongside the link 93 is not provided. The rest is the same as the prior art described above. Since the return device of this example is configured as described above, it has the following effects. first. In the return device of this example. When you press the brake pedal. Cam 86 rotates via link 93 (Fig. 5), rod 94, and pad shift lever 95. and. Push the levers 8l and 82 apart to release the brake. When the brake pedal is released, the biasing force of the brake spring 84 narrows the distance between the levers 81 and 82, and the brake is applied. In this respect, it has the same effect as a conventional brake. However. In this example, the return spring 1 is stretched between the tip 32 of the rotating arm 3 and the base plate 83, so that when the brake is released, the "." as shown in FIG. When the cam 86 is rotated by the brake pedal, the tip 32 of the rotary arm 3 rotates from the braking position A and rotates past the top dead center B against the tension of the return spring 1. death. Reach point C. That is. As shown in Figure 1. When the brake pedal is depressed, the rotating arm 3 moves along with the cam 86 to the camshaft 861.
Rotate using the fulcrum as a fulcrum. As a result, the return spring l. Since the fixing pin 41, which is the locking point on the lower end side, is located below the board 83, 1 return spring l
is stretched. At this time. The reaction force of the return spring 1 acts as a force that pulls back the brake pedal.
Then, if you continue to press the brake pedal, the rotating arm 3
rotates further and reaches the top dead center B of return spring l. here. Since the return spring 1 is stretched to the maximum, the length of the return spring 1 when the rotating arm 3 reaches the top dead center B is 1. teeth. It is longer than the length lr,is at point A during braking and point C after top dead center. Furthermore, when you press the brake pedal. The rotating arm 3 passes the top dead center B and reaches a point C. At this time, the return spring l generates a force in the same direction as when the brake pedal is depressed. On the other hand, in the brake release operation as described above, there is a force exerted on the brake pedal in addition to the reaction force of the return spring mentioned above. After the cam 86 contacts the adjustment bolt 7l (after reaching the braking point), the reaction force of the brake spring 84 acts as a force that pushes back the brake pedal. Therefore, the force on the brake pedal is. At the final point C, the reaction force of the brake spring 84 and . Above return spring I
(However, at this point, the force in the direction of the brake pedal depression force) is the resultant reaction force G. Figure 3 is. When the above brake is released. It is a diagram showing the relationship between the stroke (depression length) S of a brake pedal and the depressing force D of the same pedal. As can be seen from the above and the same figure. The reaction force E of the return spring becomes a force that reduces the pedal effort after top dead center. Therefore. Even if the reaction force F of the brake spring is applied after the brake is released (brake point P). The overall resultant reaction force G decreases. therefore. According to this example, it is possible to provide a brake pedal return spring that can reduce the pressing force on the brake pedal. In contrast, with conventional brakes, as shown in Figure 4. The depression force D of the brake pedal 9l is determined by the reaction force J of the spring 92 and the reaction force K of the brake spring 84 after the brake point P.
The resultant reaction force is H. That is, the reaction forces J and K that increase together
This becomes a resultant reaction force H, which increases as the two are added together. Therefore, the brake pedal depression force D is. The larger the pedal stroke S, the greater the increase. This places a burden on the driver. Also. The return spring 1 is. To apply the brakes. When you take your foot off the brake pedal, a force is generated that returns the pedal to its original position (i.e., a return force).5 Return the pedal to its original position. Also. The above return spring is. It is attached to the brake body and located at a high position, so it does not collect dust on the road. Rainwater etc. splashes up. There are no negative effects from this. Also. In this example brake. Even if the links (joints numbered 91, 92, 93 in Fig. 5) are loose due to wear and tear, the weight of the brake pedal and rod 94 will cause the brake pedal to move. This backlash can be absorbed. On the other hand, in conventional brakes, when the cam 86 and the adjustment bolt 71 are not in contact with each other. This is because the cam 86 is in an unstable state. The pedal stroke increases by the amount of play in the link 93. As a result, it was difficult to perform subtle brake operations near the brake point P mentioned above. On the contrary,
According to the brake in this example. As mentioned above《. Brake operation and speed adjustment are easy to perform, and the brake pedal force can be reduced.

[Brief explanation of the drawing]

Figures 1 to 4 show the return device of the embodiment; Figure 1 is a side view thereof, Figure 2 is a plan view thereof, and Figure 3 is a graph showing the relationship between pedal depression force and stroke in the present invention. , Figure 4 is a graph showing the relationship between the pressing force and stroke of a conventional pedal. Figures 5 to 7 show conventional brake devices. Figure 5 is an overall explanatory diagram. Figure 6 is its plan view, and Figure 7 is its side view. 1. ．． , return spring. 3. ．． ．． Rotating arm, 4. ,,Bracket, 71,,. Adjustment screw 81.82. ．． ．． Lever 83. ．． ．． Substrate, 84...Brake spring, 86. 、． Cam, Fig. 2 Fig. 1 Fig. 3 Fig. 5

Claims (1)

[Claims] a pair of levers whose proximal ends are pivotably connected to each other;
A board that supports both levers on the vehicle body, a pad provided inside both levers to sandwich the brake disc, a brake spring that biases both levers toward each other, and a space between the tips of both levers. A brake having a cam that is provided on the cam and rotates in a direction to push both levers apart, and a brake pedal that is connected to rotate the cam,
A rotating arm is provided that rotates integrally with the cam, and a return spring is stretched between the tip of the rotating arm and the base plate, so that when the cam is rotated by the brake pedal, A brake pedal return device characterized in that the rotating arm is configured to rotate beyond top dead center against the tension of the return spring.