JPS6228019B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to a turnover mechanism for reducing the pressing force of a clutch pedal in a friction clutch for a vehicle.

In a general turnover mechanism, a rotating arm for turnover is connected with a rod or lever so that it rotates in conjunction with the operation of the clutch pedal, and a tension is installed between the rotating arm and the clutch pedal side. It has a spring-equipped structure. In other words, with this configuration, when the clutch pedal is depressed to a predetermined stroke position, the tension spring, which had been acting on the pedal in the return direction, switches to assist the pedal depression force. This works to reduce the force required to press the pedal.

By the way, in conventional turnover mechanisms, after the point where the direction of action of the tension spring on the clutch pedal switches as described above (hereinafter referred to as the "turnover point"), the force that assists the pedal force on the clutch pedal is reduced. This gives the driver a feeling of fatigue as the pedal force suddenly increases and suddenly becomes lighter. This means that for drivers who have become accustomed to the conventional pedal feel, that is, the sensation that the pedal force increases as the pedal stroke progresses, a sudden reduction in the pedal force will actually lead to a worsening of the feeling.

Furthermore, at the above-mentioned turnover point, it goes without saying that the direction of force acting at the connection portion between the rod and the clutch pedal and the connection portion between the rod and the rotating arm is abruptly switched. The connecting portions are connected, for example, by a pivot between a pin and a pin hole, and there is usually a gap between them that is necessary for relative rotation. Due to the existence of this gap, when the direction of the force acting on the rod suddenly switches as described above at the above-mentioned turnover point, both joints produce a banging sound, and the shock of the joints at this time causes a banging sound. This will also have a negative effect on the operating feeling of the clutch pedal.

In view of these conventional circumstances, the present invention has been developed to ensure that the auxiliary action of the pedal depression force does not give a sense of discomfort to the pedal feeling, and also to reduce the interaction between the rod and the pedal at the turnover point associated with depression of the clutch pedal. It is an object of the present invention to provide a turnover mechanism capable of suppressing hitting noise at a connecting portion and a connecting portion between a rod and a rotating arm, and also preventing adverse effects on pedal feeling caused by the shock at that time.

Next, the configuration of the present invention will be explained in detail according to embodiments shown in the drawings.

First, in FIGS. 1 and 2, a clutch pedal 1 is arranged so as to be rotated about a pedal shaft 2 when the clutch pedal 1 is depressed. That is, the clutch pedal 1 is mounted such that its pedal boss 1a is rotatable about the pedal shaft 2 fixed to the pedal bracket 20 on the body side shown in FIG. The clutch pedal 1 is connected by a clevis pin 5 to a clevis 4 connected to a push rod 3 of a clutch master cylinder (not shown).

Behind the clutch pedal 1 (right side in Figure 1)
, the rotation arm 7 for turnover is connected to the second
It is rotatably attached to a part of the body 20a shown in the figure. In other words, this rotating arm 7
The boss 7a formed at one end of the body 20
It is rotatably mounted around a seam shaft 8 fixed to a. and,
The other end (free end) of this rotating arm 7 and a portion of the clutch pedal 1 are connected by a rod 9. Connecting portion 1 of this rod 9 to the pedal 1
1 is a pin 11 that integrally projects from the pedal 1;
a and a pivot hole formed at one end of the rod 9 are connected so that they can rotate relative to each other with a pusher 11b interposed between them (see especially Fig. 2). ). Furthermore, as is also clear in FIG. 2, the connecting portion 12 of the rod 9 to the rotating arm 7 includes a pin 12a integrally projected from the arm 7 and a pivot hole formed at the other end of the rod 9. , are connected so that they can rotate relative to each other with a bush 12b placed between them. By connecting the clutch pedal 1 and the rotating arm 7 with the rod 9 in this way, the rotating arm 7 moves in the direction of arrow A in FIG. 1 about the shaft 8 as the pedal 1 is depressed. It will rotate in conjunction. Note that the rod 9 is divided into two parts in its longitudinal direction (axial direction).
These are connected by a turnbuckle 10 so that the length in the axial direction can be adjusted.

Now, clevis pin 5 of clutch pedal 1 above.
A tension spring 13 is placed between the rod 9 and the rod 9. The engagement position of this spring 13 with the rod 9 is
It is set at an intermediate position between the two connecting portions 11 and 12 in . Moreover, this spring 13
is arranged so as to exert a tensile force on the rod 9 in a direction substantially perpendicular to its axis when the clutch pedal 1 is depressed to a turnover point, which will be described later.

Therefore, the effect on the clutch pedal 1 due to the tensile force of the spring 13 will be explained mainly with reference to FIG. First, if the tensile force of the spring 13 acting on the engagement point C between the rod 9 and the spring 13 is f, then this force f is divided into a force _f1 in the axial direction of the rod and a force f1 in the direction perpendicular to the axis of the rod. It can be broken down into ₂ parts. And the above component force r ₂
is distributed as forces f ₃ and f ₄ acting on both connecting parts 11 and 12 of rod 9.

Based on the above force f ₁ , the moment around the pedal shaft 2 acting on the clutch pedal 1 is M ₁
Based on the opposite force f′ which is equal to the force f acting on the clevis pin 5 of the clutch pedal 1, let the moment around the pedal shaft 2 acting on the clutch pedal 1 be M ₂ , and similarly the above Let the moments based on the forces f ₃ and f ₄ be M ₃ and M ₄ . So each of these moments
Expressing M ₁ to M ₄ using the formula is as follows.

M ₁ = f ₁・g M ₂ = −f′・d M ₃ = f ₃・e M ₄ = −f ₄ b/a・g The above moments M ₁ and M ₃ are calculated when the clutch pedal 1 is depressed. The moments M ₂ and M ₄ act as forces that cause the pedal 1 to return in the opposite direction (depressing force auxiliary force).

Now, when the clutch pedal 1 is in the return position shown in Figures 1 to 3, the values of the moments M ₂ and M ₄ that exert the above return force are the same as the values of the moments M ₁ and M ₃ in the opposite direction. is set to be larger than . Therefore, the clutch pedal 1 is maintained in the returned position shown in the figure.

Next, pressing force is applied to clutch pedal 1,
When this pedal 1 is operated to rotate around the shaft 2, the rotational arm 7 for turnover moves through the rod 9 as indicated by the arrow A as described above.
Interlocking rotation in the direction. When the depressing stroke of the pedal 1 passes a preset turnover point (for example, the position indicated by the imaginary line in FIG. 4), among the moments based on the spring 13, the moment acting in the direction of assisting the depressing force The values of M ₁ and M ₃ become larger than the values of moments M ₂ and M ₄ in the opposite direction. These moments M ₁ and M ₃ act on the pedal 1 as auxiliary forces for the pedal effort, and the pedal 1 is depressed to the position shown by the solid line in FIG. 4 while receiving the auxiliary force after passing the above turnover point.

In this way, the force exerted by the tension spring 13 on the clutch pedal 1 switches from the direction of return to the direction of assisting the pedal force at the turnover point. This means that the direction of action of the connecting portions 11 and 12 of the rod 9 to the pedal 1 and the rotating arm 7 is also switched to the opposite direction with respect to the turnover point. FIG. 5 shows an exaggerated representation of the phenomenon at both connecting portions 11 and 12 at this time for easy understanding. That is, each pin 11a, 12a in both connecting parts 11, 12
There is a gap between the bushings 11b and 12b on the rod 9 side, which is necessary for mutual relative rotation, or a gap due to wear of the bushings 11b and 12b. , 12, the gaps between them are greatly enlarged.

Now, as described above, when the direction of force acting on both the connecting parts 11 and 12 is switched, the relative positional relationship between the pins 11a and 12a on the pedal 1 side and the rotating arm 7 side and the rod 9 is as follows. In the range of the above-mentioned gap, the state changes from the state X indicated by the solid line in FIG. 5 to the state indicated by the two-dot chain line Z. Now, suppose each pin 11 above
The relative displacement between a, 12a and the rod 9 is the fifth
If it is assumed that the solid line state X in the figure is changed to the state shown by the two-dot chain line Z in a straight line, a tapping sound will be generated between each pin 11a, 12a and the rod 9. In addition, the shock at that time is transmitted to the clutch pedal 1, which impairs the pedal feeling.

However, in this embodiment, the spring 13 is disposed between the intermediate portion of the rod 9 and the clevis pin 5 of the pedal 1 as described above, and this spring 13 is It is set to exert a tensile force in a direction substantially perpendicular to the axis of the rod 9 in the state at the turnover point. Therefore, at the turnover point where the direction of force acting on both the connecting portions 11 and 12 is switched, the spring 13 is
The distribution forces f ₃ and f ₄ based on the tensile force f ₂ of are acting equally. Due to the action of the spring 13 on the connecting parts 11 and 12, each pin 11 mentioned above
The relative displacement between a, 12a and the rod 9 is the fifth
From the solid line state X in the figure, the state shown by the one-dot chain line Y is reached, and then the state shown by the two-dot chain line Z is reached. In other words, each pin 11a, 1
2a is always the bushes 11b and 12 on the rod 9 side.
While in contact with the inner circumferential surface of b, relative displacement is made along this. This makes it possible to avoid the above-mentioned impact on the hitting sound and pedal feel.

Incidentally, the displacement between the pins 11a, 12a and the rod 9 in both the connecting portions 11, 12 is extremely exaggerated as mentioned above, and this displacement is relative; For convenience, in FIG. 5, the rod 9 side is shown stationary and the pins 11a and 12a are moved.

Now, the tension spring 13 changes depending on the depression stroke of the clutch pedal 1.
The values of the moments M ₁ to _{M 4} due to the elasticity of the pedal are calculated in an actual device, and are expressed in terms of the relationship between the pedal stroke and the force acting on the pedal, as shown in the characteristic diagram of FIG. In this characteristic diagram, the vertical axis represents the above-mentioned acting force on the clutch pedal 1, and the horizontal axis represents the pedal stroke. Note that the plus side of the vertical axis indicates the action area in the pedal return direction, and the minus side indicates the action area in the pedal depression direction. In this example, a curve shown by a solid line was obtained from the conventional curve shown by a dotted line. What can be seen from this characteristic diagram is that the force acting on the pedal after passing the turnover point (point T in Figure 6), that is, the pedal force assist force, changes more gradually with respect to the pedal stroke than before. This means that it is increasing.

When the characteristics of a general friction clutch (for example, the characteristics of a diaphragm spring) are expressed in terms of the relationship between pedal depression force and pedal stroke, a curve as shown in FIG. 7 is obtained. When this clutch characteristic is combined with the conventional spring characteristic represented by the dotted line in FIG. 6, a characteristic diagram as shown in FIG. 8 is obtained. In other words, in the conventional model, the clutch pedal 1
As the driver depresses the pedal, the auxiliary force of the pedal effort increases rapidly. In other words, pedal 1
When the driver depresses the pedal to a predetermined stroke, the driver feels that the pedal force suddenly becomes lighter, which leads to deterioration of the pedal feeling for the reason mentioned above.

On the other hand, in this embodiment, the original clutch characteristics shown in FIG.
The characteristics shown by the solid line in the figure are combined to obtain the characteristics shown in FIG. 9. This results in
It is possible to avoid significant changes in pedal feeling due to the auxiliary effect of pedal depression force.

As described above, in the present invention, the depression stroke of the clutch pedal acts between the clutch pedal and the rod in the direction of returning the pedal until it reaches the turnover point, and once the turnover point is exceeded, the pedal depression is stopped. A tension spring acting in an auxiliary direction is provided, and the point of action of this tension spring on the rod is set so that the point of action of this tension spring on the rod is located at the middle of the connection of the rod to the clutch pedal and to the pivot arm at the above-mentioned turnover point. By setting the spring tension in a direction almost perpendicular to the axis of the spring, the single tension spring described above can provide a return force and an auxiliary force to the clutch pedal, and can be used as a turnover mechanism. It is now easier to control the pedal force assist force, and the pedal force assist force can be gradually increased as the clutch pedal is depressed, which can cause a sudden increase in the pedal force assist force, causing a noticeable discomfort in the pedal feeling. It has the advantage of avoiding situations.

Furthermore, when the direction of the force acting on the rod that connects the pedal and the rotational arm for turnover changes around the turnover point, the connection between the rod and the pedal and the rod and the rotational arm change. At the joint with the movable arm, the relative displacement occurring within the gap between the members constituting the two joints is suppressed so that these members always slide in contact with each other while being pressed in one direction. Therefore, it is possible to prevent hitting noise caused by an impactful relative displacement between the members constituting the two connecting portions, and also to eliminate the adverse effect on the pedal feeling caused by the shock at that time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a front view of a clutch pedal equipped with a turnover mechanism, FIG. 2 is an enlarged rear view of the main parts as seen from the right side of FIG. 1, and FIG. A part of Fig. 1 is an explanatory diagram showing the distribution of force based on the elasticity of the tension spring, Fig. 4 is a front view showing the operating state when the clutch pedal is depressed, and Fig. 5 is the connection between both rods. An enlarged plan view in which the gaps between each pin and the bushing are exaggerated to make it easier to understand the action of the
Figure 6 is a characteristic diagram that shows the relationship between the force acting on the clutch pedal based on the elasticity of the spring and the pedal stroke in comparison with the conventional one, and Figure 7 shows the characteristics of the spring in the clutch cover of the friction clutch with pedal depression force. Figures 8 and 9 show the characteristics of the friction clutch in relation to the pedal stroke and the conventional turnover mechanism and the turnover mechanism of this embodiment. FIG. 3 is a characteristic diagram showing the relationship between the pedal stroke and the pedal stroke. 1...clutch pedal, 5...clevis pin,
7... Rotating arm for turnover, 9... Rod, 11, 12... Connection portion, 13... Tension spring.

Claims (1)

[Claims] 1. The clutch pedal and the rotational arm for turnover are connected by a rod so that the rotational arm rotates in conjunction with the depression operation of this pedal, and the clutch is connected between the rod and the clutch pedal. A tension spring is provided which acts in the direction of returning the pedal until the pedal depression stroke reaches the turnover point, and acts in the direction of assisting the pedal depression once the turnover point is exceeded. The point of application is set so as to apply a spring tension in a direction substantially perpendicular to the axis of the rod to the intermediate portion of the connecting portion of the rod to the clutch pedal and the rotating arm at the turnover point. Clutch pedal turnover mechanism.