JPH0341155Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an accumulator for absorbing hydraulic vibrations (pulsations) generated in a hydraulic circuit in a hydraulic clutch release system of a vehicle.

(Prior Art) Conventionally, a piston that is pushed and moved by receiving hydraulic pressure from the hydraulic circuit is installed in the body of an accumulator that is incorporated in the hydraulic circuit of the clutch release system.
There is a structure that incorporates a damper made of an elastic material such as rubber that is compressed by the movement of the piston at this time (see, for example, Japanese Utility Model Publication No. 59-8023). When hydraulic vibration from the clutch release system acts within the accumulator body, the piston operates while compressing the damper, thereby functioning to damp the hydraulic vibration.

(Problems to be Solved by the Invention) As a matter of course, in the conventional accumulator described above, the smaller the spring constant of the elastic body used in the damper, the better the damping effect of the above-mentioned hydraulic vibration. However, when trying to increase the damping effect of hydraulic vibration by lowering the spring constant of the damper,
Along with this, the amount of deflection of the damper increases and the operating stroke of the piston increases. This causes problems such as an increase in the invalid stroke of the clutch release system, that is, the stroke cross of the clutch pedal. As a countermeasure to this problem, it is possible to apply preload to the damper and install it in a compressed state, but the problem is that in the compression region caused by this preload, the above-mentioned damping effect of the hydraulic vibration is not achieved at all. occurs.

(Means for Solving the Problems) Therefore, the hydraulic clutch release type accumulator according to the present invention is constructed as follows.

That is, as is clear from FIG. 1, the damper 20 incorporated in the body 1 is actuated by the piston 13 which operates in response to hydraulic vibration from the hydraulic circuit of the hydraulic clutch release system within the accumulator body 1. In the accumulator configured to elastically deform in the compression direction and thereby absorb hydraulic vibration, the damper 20 includes a first elastic body 21 and a second elastic body 22 arranged along the operating direction of the piston 13. It is configured. The first elastic body 21 is assembled in a compressed state in which the end surface of the first elastic body 21 in contact with the second elastic body 22 is received by the stepped portion 11a in the accumulator body 1. Further, the second elastic body 22 is incorporated between the piston 13 and the first elastic body 21, and
The spring constant is set to start elastic deformation in the compression direction from the initial stage of operation.

(Function) According to the above configuration, the first elastic body 21 to which a preload is applied by being incorporated into the accumulator body 1 in a compressed state has a spring constant equal to that of the second elastic body 2.
It becomes larger than 2. Therefore, the piston 1
When the vibration load of the release system hydraulic pressure acting on the release system 3 is small, only the second elastic body 22 having a small spring constant is compressed. When this vibration load exceeds the spring constant of the first elastic body 21, this first elastic body 21
compression is also started. In other words, the spring characteristic of the damper 20 is that until the vibration load acting on the piston 13 reaches the spring constant of the first elastic body 21, the vibration load is based on the spring constant of only the second elastic body 22, and the vibration load is applied to the first elastic body 21. From the time when the spring constant is exceeded, both elastic bodies 21 and 22 are based on the combined spring constant.

As a result, the damper 20 has multi-stage spring characteristics,
As a result, hydraulic vibrations can be appropriately damped in the entire stroke range of the piston 13 without increasing the operating stroke of the piston 13.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

First, the first section showing the longitudinal section of the accumulator is
In the drawings and FIG. 2, which is a cross-sectional view taken along the line 1 in FIG. A piston 13 is built into the accumulator body 1 so as to be slidable in the left-right direction in FIG. is configured. Incidentally, this accumulator body 1 is incorporated into a hydraulic circuit of a hydraulic clutch release system (not shown), and a pair of ports 4 and 5 communicating with the above-mentioned hydraulic chamber 10 are formed in this body 1. There is. One port 4 is connected to a clutch master cylinder (not shown) of the clutch release system through a pipe 8 connected thereto by a flare nut 6, and the other port 5 is connected to a pipe 9 also connected by a flare nut 7. It communicates with a clutch release cylinder (not shown) through it.

In the body 1, the piston 13 is located between the piston 13 and the bracket 2.
A damper 20 that is elastically compressed and deformed by operating rightward from the state shown in the figure is incorporated. This damper 20 is constructed by arranging a first elastic body 21 and a second elastic body 22, each made of an elastic material such as rubber, along the operating direction of the piston 13 (left-right direction in FIG. 1). .

The first elastic body 21 is assembled in a compressed state between the bracket 2 and the plate 23, which is received at the stepped portion 11a of the large diameter portion 11 in the body 1. As a result, a predetermined preload is applied to the first elastic body 21, and its spring constant is set larger than the spring constant of the second elastic body 22.

In addition, the piston 1 in the above-mentioned hydraulic chamber 10
3 and the inner wall of the body 1 is this piston 1.
A conical spring 15 is built in so as to lightly press the spring 3 toward the damper 20.

Further, in the accumulator body 1, a tapered surface 12 is formed between the piston cup 14 and the ports 4 and 5 of the body 1 on the inner circumferential surface of the body 1, which is the sliding surface of the piston 13. It is formed. Thereby, when air is removed from the accumulator body 1, air bubbles attached to the piston sliding surface within the body 1 can be appropriately sent out along the tapered surface 12 to an air release port (not shown). As a result, unlike conventional accumulators in which the piston sliding surface inside the body is sloped, the body The degree of freedom in the shape of the bracket 2 that fixes the pump 1, the mounting space for the accumulator, the piping of the hydraulic pipes 8 and 9, etc. is increased.

In the accumulator constructed as described above, the hydraulic pressure in the hydraulic circuit of the clutch release system is constantly applied to the hydraulic chamber 10 in the body 1 through the pipes 8 and 9 and the ports 4 and 5. In the hydraulic circuit of this clutch release system, for example, when the clutch is connected or disconnected, mechanical vibrations are transmitted to the release piston in the clutch release cylinder (not shown).
This movement of the release piston causes hydraulic vibrations within the hydraulic circuit. This hydraulic vibration acts on the piston 13 from the above-mentioned hydraulic chamber 10, and this piston 13 acts on each elastic body 2 constituting the above-mentioned damper 20.
1 and 22, it operates to the right in FIG. At this time, the internal hysteresis accompanying the compressive deformation of each elastic body 21, 22 absorbs the vibration load acting on the piston 13, thereby damping the hydraulic vibration.

Now, in the damper 20 of this embodiment, the spring constant of each of the elastic bodies 21 and 22 constituting the damper 20 changes depending on the change in the above-mentioned hydraulic vibration, that is, the change in the vibration load on the piston 13, when this load is small. Only the second elastic body 22 with a smaller amount is compressed. Therefore, when the vibration load acting on the piston 13 exceeds the compression load due to the preload on the first elastic body 21, the compression of the first elastic body 21 is also started. That is, as for the spring characteristics of the damper 20, until the vibration load acting on the piston 13 based on hydraulic vibration reaches the compressive load due to the preload of the first elastic body 21, the spring constant of the second elastic body 22 alone becomes the spring constant. After the compressive load due to the preload is exceeded, the spring constant becomes a composite of the elastic bodies 21 and 22.

Here, when the spring characteristics (load deflection characteristics) of the damper 20 of this embodiment are examined in comparison with a conventional damper, it is found that when the damper 20 of this embodiment is used, With the change in the amount of deflection δ of the shaft (stroke amount of the piston 13),
From the initial point in time, the spring characteristics of the second elastic body 22 with a small spring constant are exhibited. This means that
It becomes possible to compensate for the vibration damping effect in the area where the conventional damper cannot exhibit the vibration damping function under the load W on the vertical axis, that is, in the area indicated by the compressive load W1 due to the preload.

Furthermore, the second elastic body 22 allows the spring constant of the damper 20 to be set small in a region close to the load W3 when the clutch is disengaged in FIG. As a result, the clutch pedal (not shown)
This increases the damping effect of hydraulic vibrations when the clutch pedal is pressed down, improving the feeling of operating the clutch pedal.

Furthermore, in the damper 20 of this embodiment, as shown in FIG. 3, the total deflection δ1 is smaller than the total deflection δ2 of the conventional damper, making it possible to suppress the stroke cross of the clutch pedal. Note that the load W2 shown on the vertical axis in FIG. 3 indicates the preload compression load of the first elastic body 21 in the damper 20 of this embodiment.

The embodiment shown in FIG. 4 omits the piston 13 in the previous embodiment, uses a piston cup 24 instead of the piston 13, and uses the second elastic body 22 in the damper 20 of the previous embodiment in the piston cup 24. It also has functions. That is, in the embodiment shown in FIG. 4, the piston cup 24 is connected by the coil spring 25 to the first elastic body 21, which is assembled in a compressed state with preload applied as in the previous embodiment. The piston cup 24 is made of an elastic material having a smaller spring constant than the first elastic body 21. According to this embodiment, the hydraulic vibration acting on the hydraulic chamber 10 is directly received by the piston cup 24 made of an elastic material, so the hydraulic vibration from the hydraulic circuit of the clutch release system is This solves the problem of the vibration being reflected by the piston 13 and being difficult to properly transmit to the damper 20.

Further, in this embodiment, the piston cup 24 and the first elastic body 21 can exhibit the same function as the damper 20 of the above-described embodiment, that is, two-stage spring characteristics against hydraulic vibration. Therefore, the function as an accumulator can be improved, and at the same time, the structure can be made smaller and simpler, and costs can be reduced.

In the embodiment shown in FIG. 4, parts that are considered to have the same or equivalent configuration as the embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals in the drawings, and redundant explanations will be omitted.

(Effects of the invention) As described above, even if the first elastic body and the second elastic body constituting the damper are both made of the same material, the present invention applies a preload to the first elastic body to change its spring constant to a second elastic body. By making the damper larger than a two-elastic body, the damper can exhibit multi-stage spring characteristics, and the hydraulic pressure can be maintained throughout its entire stroke without increasing the operating stroke of the piston, which operates in response to hydraulic vibration. It is possible to exhibit a vibration damping effect.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view showing an accumulator of a hydraulic clutch release system, Fig. 2 is a sectional view taken along the - line in Fig. FIG. 4 is a characteristic diagram showing a comparison of the spring characteristics (load-deflection characteristics) of the conventional damper and a conventional damper, and FIG. 4 is a longitudinal cross-sectional view showing an accumulator of a different embodiment. 1... Accumulator body, 13... Piston, 20... Damper, 21, 22, 24... Elastic body constituting the damper.

Claims (1)

[Scope of Claim for Utility Model Registration] A damper built into the accumulator body built into the hydraulic clutch release system is actuated by a piston that operates in response to hydraulic vibration from the hydraulic circuit. In an accumulator configured to elastically deform in a compression direction and thereby absorb hydraulic vibrations, the damper is composed of a first elastic body and a second elastic body disposed along the operating direction of the piston, and The first elastic body is assembled in a compressed state with its end surface in contact with the second elastic body being received by a step in the accumulator body, and the second elastic body is installed between the piston and the first elastic body. incorporated into
A hydraulic clutch release type accumulator, characterized in that the spring constant is set so that the piston starts elastic deformation in the compression direction from the initial stage of operation.