JPS61278604A - Fluid pressure operation device - Google Patents

Abstract

PURPOSE:To simplify structure and reduce the cost by housing the first and the second spool valves, driven by a piston, in a cylinder main body and providing an energizing means, which energizes the piston in one direction, on the piston. CONSTITUTION:The first and second spool valves 7a, 7b driven by a piston 3 are housed, so as to freely reciprocate, in holes 6a, 6b which are drilled in a cylinder main body 2. Further, a compression coiled spring 30, arranged between a spring bearing 28 fixed to the main body 2 and a flange 29 fixed to a piston rod 4, energizes the piston 3 in one direction. Since this eliminates requirement for a costly control circuit for controlling changeover means which alternately change over and supply hydraulic fluid to each operational chamber 1a, 1b, structure of a fluid pressure operational device is simplified and its cost can be reduced.

Description

[Detailed description of the invention] 1st summer TECHNICAL FIELD This invention relates to fluid pressure actuated devices.

BACKGROUND OF THE INVENTION Fluid pressure actuators are well known in the art that use fluid pressure, such as hydraulic pressure or pneumatic pressure, to reciprocate a piston and use the actuation force as a drive source for various devices. A piston mounted reciprocally in a piston chamber partitions the piston chamber into two working chambers, and the piston is caused to reciprocate by alternately supplying and discharging working fluid to these working chambers. In this case, in conventional devices of this type, it has been necessary to use switching means, such as a solenoid valve or a cam, for the purpose of alternately supplying working fluid to each working chamber.

However, if such a switching means is used, an expensive control circuit for electrically controlling it is required, which inevitably increases the cost of the device.

The present invention has been made based on the above recognition, and its purpose is to provide a fluid pressure actuated device that eliminates the need for a conventional expensive control circuit, reduces costs, and simplifies the configuration. The goal is to provide the following.

The present invention provides a piston that is reciprocably arranged in a piston chamber and partitions the piston chamber into a first and a second working chamber;
first and second spools belonging to the first and second working chambers and supported in a reciprocating manner; first and second inlet passages leading to the pump;
first and second outlet passages leading from the first and second working chambers, respectively, to an outlet via holes containing the first and second spools; and second and second outlet passages, opposite from the first and second working chambers, respectively. first and second discharge passages leading to the outlet through a hole containing the first spool;

The first and second spools include first and second biasing means for biasing the first and second spools toward the piston, respectively, and piston biasing means for biasing the piston toward one end when no load is applied.
and a second spool is closest to the piston so that it can be pressed by the piston, and blocks the first or second inlet passage and the second or first discharge passage;
and a first position opening the first or second exit passage;
a second position for blocking all of the first or second inlet passage, the second or first discharge passage, and the first or second outlet passage; and opening the first or second inlet passage.

a third position for blocking the second or first outlet passage and the first or second outlet passage; and a third position for blocking the first or second outlet passage and for blocking the first or second inlet passage and the second or first outlet passage; A fluid pressure actuated device is proposed which is switched by the first or second biasing means, the piston and fluid pressure to a fourth position in which the fluid pressure is released. According to this configuration, the piston can be caused to reciprocate by alternately supplying the working fluid to each working chamber using the fluid pressure, the urging means, and the movement of the piston itself, without providing an independent control circuit.

member of staff Embodiments of the present invention will be described below with reference to the drawings.

The fluid pressure actuated device shown in FIGS. 1 and 2 has a main body 2 having a cylindrical or other shaped piston chamber 1 therein.
A piston 3 having a shape corresponding to the cross-sectional shape of the piston chamber 1 is installed in the piston chamber 1 so as to be able to reciprocate in the directions of arrows A and B. A piston rod 4 is fixed at the center of the piston 3.

It slidably penetrates the end walls 5a and 5b of the main body 2.

Each end thereof protrudes outside the main body 2.

3 to 10 are cross-sectional explanatory views schematically showing each element of the fluid pressure actuated device shown in FIGS. Rod 4 is not shown.

As can be seen from FIGS. 1 to 3, the piston chamber 1 is partitioned by the piston 3 into a first working chamber 1a on the right side in the figure and a second working chamber 1b on the left side, and a hole 6 formed in the main body 2
First and second spools 7a and 7b are housed in a and 6b so as to be able to reciprocate in the same direction as the piston 3. 8a and 8b in FIG. 1 and FIG. 2 represent holes 6a and sb.
These plugs are removably screwed onto the main body 2 and are removed when the spools 7a, 7b are attached or detached.

The spools 7a and 7b have their distal ends facing each other forming small diameter portions 9a and 9b, and these distal end small diameter portions 9a and 9b form intermediate large diameter portions 11a and 11b via tapered portions 10a and 10b, respectively. llb, then intermediate small diameter portions 12a, 12b, rear end large diameter portions 13a, 13b,
Flange-shaped stoppers 14a and 14b are provided at the rearmost end.

In the outermost spaces 15a and 15b of the number holes 6a and 6b, a first
and second helical compression springs 16a, 16b are housed, respectively, and these springs 16a, 16b actuate each spool 7a, 7.
b is biased in the direction facing the piston 3.

Further, in this example, plate-shaped valve members 18a, 18b made of an elastic or flexible material such as rubber are provided on each end surface 17a, 17b of the piston 3, as shown in FIG. has a through hole 19a, 1 in its center.
9b is formed, and its outer peripheral base is the end surface 17 of the piston 3.
a, 17b. 20 is an O-ring fitted into the circumferential groove of the piston 3.

In FIG. 3, the main body 2 has first and second spools 7a and 7b inserted therein through holes 6a and 6b that accommodate the spools 7a and 7b. Second working chamber 1a, l
first and second inlet passages 21a, 21 respectively leading to
b is formed, and these inlet passages 21a and 21b are connected to the inlet 22
and is connected via a conduit 24 to a pump 23 which is separate from the main body 2. Furthermore, first and second working chambers 1a,
First and second outlet passages 25a and 25b are respectively opened in lb, and these outlet passages 25a and 25b are connected to the first and second spools 7a on the sides to which they belong.

It merges into the outlet 26 via holes 6a and 6b containing the hole 7b. Similarly, the first and second working chambers 1a.

1b has first and second discharge passages 27a, 27b open therein, and these discharge passages 27a, 27b are connected to holes 6b, 6a for spools belonging to the working chamber on the opposite side from the working chamber in which these discharge passages 27a, 27b open. The outlet 26 is reached via the outlet 26. That is, the first discharge path 27a extends inside the main body 2 from the first working chamber 1a, reaches the hole 6b that accommodates the second spool 7b, and from there reaches the outlet 26; The outlet 26 is reached through the hole 6a for the opening 7a.

The first spool 7a can occupy the first to fourth positions shown in FIGS. 11 (I) to (mV).

A second spool 7b arranged symmetrically with the first spool 7a
can also occupy the first to fourth positions symmetrical to FIGS. 11(1) to (IV). In this way, each spool 7a
, 7b, the above-mentioned inlet passages 21a, 21b, outlet passages 25a, 25b and discharge passage 2
7a, 27b are shut off or opened by each spool 6 The details thereof will be explained below together with the operation of the actuating device. In addition, in FIGS. 3 to 10, each spool 7a.

The symbols ``■'' to ``■'' attached to 7b indicate the positions occupied by each spool.

As shown in FIGS. 1 and 2, a spring receiver 28 that slidably supports the piston rod 4 is fixed to the main body 2.
A compression coil spring 30 is arranged between this spring receiver 28 and a flange 29 fixed to the piston rod 4. Therefore, when the pump 23 is not supplying working fluid and the device is not operating, the piston 3 is biased by the spring 30 and remains stationary at the rightmost initial position shown in FIG. Piston biasing means other than the spring 30 may also be used.

Further, the spring may be arranged so that the rightmost piston position is the initial position.

When the piston 3 is in the initial position shown in FIG.

The first spool 7a is pressed by the right end surface 17a of the piston 3 and moves to the third position (
It occupies the position shown in Figure 11 (III). When the first spool 7a occupies the third position in this way, the first spool 7a is inserted into the first working chamber 1a through the gap between the tip small diameter portion 9a of the first spool 7a and the hole 6a. Therefore, the first person 0 path 21a is in an open state. On the contrary, the first outlet passage 25a is blocked by the intermediate large diameter portion 11a of the first spool 7a- which has entered the hole 6a. Also, the second discharge path 2
7b as well, its flow path is blocked by the rear end large diameter portion 13a of the first spool 7a.

On the other hand, the second spool 7b is pushed to the right by the second spring 16b as seen in FIG.
is stopped against the step between the hole 6b and the space 15b (first position shown in FIG. 11(1)). At that time, the second
The tip of the spool 7b protrudes into the second working chamber lb, and the second person concave passage 21b and the first discharge passage 27a are connected to the second spool 7.
The flow path is blocked by the intermediate large diameter portion 11b and the rear end large diameter portion 13b of b. Conversely, the second exit path 25
b communicates with the outlet 26 via the intermediate small diameter portion 12b of the second spool 7b, and its flow path is in an open state.

When the pump 23 starts operating in the above-mentioned state and pressurized working fluid (which can be either liquid or gas, but in this example, it is liquid) is sent into the inlet 22, this liquid moves as indicated by arrow C. As shown, it flows into the first working chamber 1a through the first zero passage 21a.

On the other hand, since the second concave passage 21b is blocked, liquid is not supplied to the second working chamber 1b.

Since the liquid is supplied to the first working chamber 1a in this way, the liquid pressure acts on the tapered portion 10a of the first spool 7a located in the hole 6a, and the spool 7a moves into the first working chamber 1a against the action of the first spring 16a. It slides to the right in FIG. 3 and stops at the rightmost fourth position (FIG. 11 (■)) as shown in FIG. Therefore, the second discharge path 27b on the second working chamber 1b side, which had been blocked by the first spool 7a, is opened, but the first outlet path 25a remains blocked. The second spool 7b maintains the same first position as in FIG.

As mentioned above, the pressurized liquid is supplied only to the first working chamber 1a, and the second outlet path 2 opens to the second working chamber 1b.
5b remains open and the second discharge path 27b is opened, so the piston 3 starts sliding toward the left in FIG. 4, and the liquid in the second working chamber 1b is discharged from the outlet 26. .

This state is shown in FIG. 5, with the first and second spools 7a, 7b still occupying the same fourth and first positions as in FIG. 4, respectively.

When the piston 3 approaches its left end position, the left end surface 17b of the piston 3 hits the tip of the second spool 7b and pushes it, as shown in FIG.
It slides from the position to the second position also shown in FIG. 11 (II). by this.

Although the second outlet path 25b is blocked by the intermediate large diameter portion tib of the second spool 7b, the first spool 7a remains in the fourth position, so the second discharge path 27b remains open. , the liquid in the second working chamber lb is discharged to the outside through the outlet 26, for example to a tank (not shown).

The piston 3 continues to push the second spool 7b to the left while sliding to the left, and finally reaches the leftmost position shown in FIG. At this time, the second spool 7b is pressed by the piston 3 and reaches the third position (FIG. 11 (■)). Therefore, the second concave passage 21b is open, the second exit passage 25b is blocked, and the first discharge passage 27a is blocked.
Pressurized liquid from the pump 23 flows into the second working chamber 1b through 1b. At this time, the left end surface 17b of the piston 3
is blocking the openings of the second discharge path 27b and the second outlet path 25b via the valve member 18b, the pressure in the second working chamber lb increases, and the tapered portion 10b of the second spool 7b is pressurized. As shown in FIG. 8, the second spool 7b is pushed into the fourth position at the leftmost end ((■) in FIG. 11). Therefore, the intermediate small diameter portion 12b of this spool 7b is aligned with the first discharge path 27a, and the discharge path 27a is opened. Therefore, the first working chamber 1a communicates with the outlet 26 via the first discharge path 27a, and the pressure in this working chamber 1a decreases. the result,
The first spool 7a, which had previously occupied the fourth position due to the hydraulic pressure in the first working chamber 1a, slides to the left under the action of the first spring 16a, and returns to the first position as shown in FIG. occupies

As a result, the first person-free passage 21a is shut off, stopping the supply of liquid to the first working chamber 1a, the first outlet passage 25a is opened, and the second discharge passage 27b is shut off. Second spool 7b
remains in the fourth position. Therefore, the pressurized liquid continues to be supplied to the second working chamber 1b, and the first working chamber 1
The liquid a is discharged to the outside through the first outlet passage 25a and the first discharge passage 27a, and the piston 3 begins to move to the right as shown in FIG.

The above-described operation is repeated, and the piston 3 repeats the reciprocating motion. When the operation of the pump 23 is stopped, the piston 3 returns to the initial position by the spring 30 and stops. In this way, the piston 3 and its piston rod 4 can be operated simply by supplying pressurized liquid from the pump 23 to the inlet 22, and electrical control is required to switch and supply the liquid to each working chamber. No circuit is required.

By the way, in the illustrated example, each end surface 17a of the piston 3
, 17b are provided with valve members 18a, 18b,
These functions are as follows.

That is, when the piston 3 approaches its leftmost position but has not yet reached its leftmost position.

In other words, when the piston 3 moves slightly to the left from the position shown in FIG. The opening of 27b is closed.

At this time, the second spool 7b is in the second position (FIG. 6) and the third position If! (FIG. 7), the second working chamber 1b is already open, although not fully open, and pressurized liquid is supplied to the second working chamber 1b. Therefore, the pressure in the first working chamber 1a increases just before the piston 3 reaches the leftmost position, and at this time the pressure in the first working chamber 1a is also high, so that the pressures in the rain working chambers 1a and 1b are substantially unbalanced. In this state, the piston 3 reaches the leftmost position shown in FIG. 7 due to its inertia. In this way, the pressure in the second working chamber 1b increases before the piston 3 reaches the leftmost position, so a buffering effect acts on the piston 3, preventing the piston 3 from reaching the leftmost position shockingly. The noise generated by the operation is suppressed. Naturally, when the piston 3 reaches its rightmost position, the same function is achieved by its first valve member 18a. Also, after the valve member closes the openings of the outlet passage and the discharge passage, the piston 3 is at the leftmost position shown in FIG. It is also possible to configure the piston 3 to stop due to the resistance force acting on it just before reaching the rightmost position (or the rightmost position), to make this position the final position, and to operate in the opposite direction again. Of course, it is also obvious that the valve member may be omitted and the end surfaces 17a, 17b of the piston 3 may be configured to close the openings of the outlet passage and the discharge passage.

The fluid pressure actuated device according to the present invention can be used for various purposes,
For example, it can be advantageously used as a driving device for an automobile windshield wiper or a heat lamp glass wiper. Particularly, if the present invention is adopted in a headlamp glass wiper, uses a cleaning liquid as the working fluid, and sprays the cleaning liquid discharged from the working chamber onto the headlamp glass, an advantage can be obtained that the working fluid can be used effectively. FIG. 13 shows an example.

In FIG. 13, intermediate links 31a and 31b are pivotally attached to each tip of the piston rod 4 fixed to the piston 3 of the fluid pressure actuated device described above, and these links include the following:
Blades 33a and 33b for wiping headlamp glass 32a and 32b of an automobile are connected, and each link 3
1a and 31b are supported so as to be able to swing about this connection point as a fulcrum.

When the actuating device operates and the piston 3 and piston rod 4 reciprocate left and right, each link 31a, 31b swings about its fulcrum together with the blades 33a, 33b, and each blade 33a, 33b moves toward the glass 32a.
, 33a. The outlet 26 of the actuator is also connected via a discharge conduit 34 to an ejection nozzle 35a, 35b located in the vicinity of each glass 32a, 32b. Therefore, the liquid (cleaning liquid) discharged from the outlet 26 is directed to each nozzle 35a.

The liquid is ejected from 35b onto the glasses 32a, 32b, and the glasses 32a, 32b are effectively cleaned by the cooperative action of this liquid and the wiping action of the blades 33a, 33b. As described above, by employing the actuating device according to the present invention as a wiper drive device, it is possible to obtain a wiper with a simple structure and low cost.

According to the present invention, there is no need for an expensive control circuit for controlling the switching means that alternately switches and supplies working fluid to each working chamber, and the structure of the fluid pressure operating device is simplified.
It has become possible to reduce the cost.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an example of a fluid pressure operated device according to the present invention, Fig. 2 is a front view of Fig. 1, and Figs. 3 to 1O clarify the principle and operating state of the fluid pressure operated device. 11(1) to (rV) are cross-sectional explanatory views showing each position occupied by each spool, FIG. 12 is a perspective view of the piston, and FIG. 13 is an explanatory diagram schematically showing the device. FIG. 2 is an explanatory diagram showing a configuration in which the actuating device is used as a driving device for a headlamp glass wiper. 1... Piston chamber 1a, lb... Working chamber 3... Piston 6a, 6b... Hole 7a
, 7b... Spools 21a, 21b... Inlet path 23... Pump 25
a, 25b...Exit path 26...Exit 27a, 2
7b-Discharge path Applicant Kanto Jidosha Kogyo Co., Ltd. Figure 1f Figure 12 Figure 13

Claims (1)

[Scope of Claims] A piston that is disposed in a reciprocating manner within a piston chamber and partitions the piston chamber into a first and a second working chamber, and a piston that belongs to the first and second working chambers and is supported in a reciprocating manner. first and second spools, respectively, and first and second inlet passages leading from the first and second working chambers, respectively, to the pump through holes containing the first and second spools; first and second outlet passages leading from the working chamber to an outlet through holes housing first and second spools and opposite second and first spools from the first and second working chambers, respectively; the first leading to the outlet via the hole;
and a second discharge path, first and second biasing means for biasing the first and second spools toward the piston, respectively, and piston biasing means for biasing the piston toward one end when no load is applied. and the first and second spools are closest to the piston so that they can be pressed by the piston, and the first and second spools are closest to the piston so as to be pressed by the piston.
or a second inlet passage, a first position that blocks the second or first outlet passage and opens the first or second outlet passage; and the first or second inlet passage, the second or first outlet passage; , and a second block blocking all of the first or second exit passages.
a third position that opens the first or second inlet passage and blocks the second or first discharge passage and the first or second outlet passage; and a third position that blocks the first or second outlet passage; Hydraulic actuation characterized in that the first or second biasing means, the piston and the fluid pressure can switch between the first or second inlet passage and the second or fourth position opening the first discharge passage. Device.