JPH0328163Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a three-position fluid pressure cylinder used, for example, when remotely controlling a manual control valve for a transmission.

(Prior Art) Conventionally, cargo handling vehicles such as container carriers have a plurality of built-in hydraulic clutches, and depending on the engagement and engagement of these clutches, forward and backward movement, including neutral, and conversion between first and third gears are performed. A transmission is used, which is equipped with manual control valves for forward and reverse travel and for shifting that control each hydraulic clutch. Each control valve is a so-called three-position control valve.

By the way, since the transmission is usually located near the driver's seat, each manual control valve provided thereon can be easily operated.

However, in container carriers and the like, the transmission often cannot be located near the driver's seat due to design considerations.

In such cases, conventionally, a three-position fluid pressure cylinder is provided to operate each manual control valve, and another manual control valve is installed in the driver's seat to control these valves for so-called remote control. I was doing it.

4-6 illustrate a conventional three-position hydraulic cylinder 50. FIG.

This is the first cylinder 51 and the second cylinder 52.
The first port 53 communicates with the rod chamber of the first cylinder 51, the second port 54 communicates with the tail chamber of the first cylinder 51, and the second port 52 communicates with the rod chamber of the first cylinder 51. A third port 55 leading to the tail chamber and a second cylinder 52
An air vent port 56 communicating with the rod chamber is provided.

By supplying pressure fluid from the third port 55 as shown in FIG. 4, the first position, for example, the neutral position N, as shown in FIG.
By supplying pressure fluid to port 4, a second position, for example, forward position F, can be obtained, and by supplying pressure fluid from first port 53, as shown in FIG. 6, a third position, for example, reverse position R, can be obtained. .

However, such a three-position fluid pressure cylinder 5
0 has two cylinders directly connected, so the overall length is long, and since there are three control ports, the structure of the manual control valve that controls these ports and the piping between them are complicated, resulting in high costs. There was a problem with it being attached.

(Problems that the invention attempts to solve) This invention was created in view of the problems mentioned above and to solve them, and its purpose is to:
To provide a three-position fluid pressure cylinder whose overall length is shortened and whose associated manual control valve and piping are simplified to reduce costs.

(Means for Solving the Problems) The three-position fluid pressure cylinder of the present invention includes a cylinder body having a first cylinder cavity inside, a first rod chamber and a first rod chamber before and after the first cylinder cavity of the cylinder body. A movable cylinder is slidably fitted to form a tail chamber and has a second cylinder cavity therein, and a second rod chamber and a second tail chamber are provided before and after the second cylinder cavity of the movable cylinder. a piston that is slidably inserted so as to form a piston, a piston rod that slidably penetrates the front portions of the cylinder body and the movable cylinder and whose rear ends are connected to the piston, and the cylinder body and the movable cylinder. a first elastic body interposed between the movable cylinder and the piston to bias the movable cylinder rearward; a second elastic body disposed between the movable cylinder and the piston to bias the piston forward; a first port that is connected to the movable cylinder and communicates with the first rod chamber; a second port that is provided in the cylinder body and that communicates with the first tail chamber; and a first port that is provided in the movable cylinder that communicates the first port with the second rod chamber. It is characterized by being composed of a passage and a second communication passage provided in the movable cylinder and communicating the second port and the second tail chamber.

In other words, it is a composite type.

(Function) When pressure fluid pressure is not supplied to the first port and the second port, the movable cylinder is on the rear side due to the first elastic body, and the piston is on the front side due to the second elastic body. The piston rod is in a first position, for example a neutral position.

When pressure fluid is supplied to the second port, it reaches the first tail chamber, so the movable cylinder moves forward against the first elastic body, and the pressure fluid reaches the second tail chamber through the second communication path. Therefore, the piston moves forward, and the piston rod moves forward by a predetermined distance from the first position to a second position, for example, a forward position.

At this time, the fluid in the first rod chamber is discharged from the first port, and the fluid in the second rod chamber is discharged from the first port via the first continuous passage.

When pressure fluid is supplied to the first port, it reaches the first rod chamber, so the movable cylinder moves rearward, and the pressure fluid passes through the first passageway and reaches the second rod chamber, so the piston moves into the second elastic body. The piston rod is moved rearward against the force, and the piston rod is moved rearward by a predetermined distance from the first position to a third position, for example, a reverse position.

At this time, the fluid in the first tail chamber is discharged from the second port, and the fluid in the second tail chamber is discharged from the second port via the second communication path.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal sectional view showing a first position of a three-position hydraulic cylinder according to an embodiment of the present invention. FIG. 2 is a similar view showing a second position. FIG. 3 is a similar view showing the third position.

The three-position fluid pressure cylinder 1 includes a cylinder body 2, a movable cylinder 3, a piston 4, a piston rod 5, a first elastic body 6, a second elastic body 7, a first port 8, a second port 9, and a first communication passage 10. , and the second communication path 11.

The cylinder body 2 has a first cylinder cavity 12 inside.
It is equipped with the following.

This consists of a bottomed cylindrical body 13, a lid body 14 that closes the front side of this body, and a collar 15 that is fixed to the rear side of this body and located on the front side of the first cylinder cavity 12.

The movable cylinder 3 is slidably fitted so that a first rod chamber 116 and a first tail chamber 17 are formed before and after the first cylinder cavity 12 of the cylinder body 2, and a second cylinder cavity 18 is formed inside the movable cylinder 3. It is equipped with the following.

This consists of a bottomed tube body 19 and a cap body 20 that closes the front side of the tube body 19. The second cylinder cavity 18 has a different diameter cavity with a large diameter on the front side, and a A sealing material 21 is interposed.

The piston 4 is slidably inserted into the second cylinder cavity 18 of the movable cylinder 3 so that a second rod chamber 22 and a second tail chamber 23 are formed at the front and rear of the second cylinder cavity 18 .

This is slidably inserted into the front side of the second cylinder cavity 18, and a second sealing material 24 is interposed between it and the movable cylinder 3.

The piston rod 5 slidably passes through the front portions of the cylinder body 2 and the movable cylinder 3, and is connected to the piston 4 at its rear end.

This is because the front part is provided with a male screw 26 into which a nut 25 is screwed, and the rear part is made to have a small diameter and is provided with a mounting male screw 27, which penetrates the lid body 14 and the cap body 20, respectively. At the same time, it is attached by passing the small diameter part through the piston 4 and screwing the mounting nut 28 onto the mounting male screw 27.
A third sealing material 29 is provided between the cap body 2 and the cap body 2.
A fourth sheet material 30 is interposed between the piston 4 and the piston 4, and a fifth seal material 31 is interposed between the piston 4 and the piston 4.

The first elastic body 6 is interposed between the cylinder body 2 and the movable cylinder 3 and urges the movable cylinder 3 rearward.

This is interposed between the lid body 14 and the cap body 20, and uses a compression type coil spring.

The second elastic body 7 includes the movable cylinder 3 and the piston 4.
It is interposed between the piston 4 and the piston 4 to urge the piston 4 forward.

This is interposed between the piston 4 and a receiver 32 installed on the rear side of the second cylinder cavity 18, and uses a compression type coil spring.

The first port 8 is provided in the cylinder body 2 and communicates with the first rod chamber 16.

This is provided closer to the front side of the bottomed cylindrical body 13.

The second port 9 is provided in the cylinder body 2 and communicates with the first tail chamber 17.

This is provided on the rear side of the bottomed cylindrical body 13.

The first communication passage 10 is provided in the movable cylinder 3 and communicates the first port 8 and the second rod chamber 222.

This consists of an axial through hole bored through the front and rear surfaces of the cap body 20, and an axially perpendicular through hole that reaches the outer periphery.

The second communication passage 11 is provided in the movable cylinder 3 and communicates the second port 9 and the second tail chamber 23.

This consists of an axial through hole penetrating the bottom wall of the bottomed tube body 19 and a through hole extending through the receiving body 32 continuously from the through hole.

Next, the operation will be explained based on such a configuration.

When pressure fluid is not supplied to the first port 8 and the second port 9, as shown in FIG. At the same time, the piston 4 is located on the front side, abutting the cap body 20 by means of the second elastic body 7, so that the piston rod 5 is in a first position, for example a neutral position N.

When pressure fluid is supplied to the second port 9, the pressure fluid reaches the first tail chamber 17, as shown in FIG. As well as moving to
Pressure fluid passes through the second communication passage 11 and enters the second tail chamber 2.
3, the piston 4 moves forward until it comes into contact with the cap body 20, and the piston rod 5 moves forward by a predetermined distance a from the first position to a second position, for example, the forward position F.

At this time, the fluid in the first rod chamber 16 is discharged from the first port 8, and the fluid in the second rod chamber 22 is discharged from the first port 8 via the first continuous passage 10.

When pressure fluid is supplied to the first port 8, the pressure fluid reaches the first rod chamber 16, as shown in FIG. At the same time, the pressure fluid reaches the second rod chamber 22 through the first continuous passage 10, so the piston 4 moves rearward against the second elastic body 7 until it comes into contact with the bottom wall of the bottomed tube body 19. However, the piston rod 5 moves backward from the first position by a predetermined distance b (equal to the predetermined distance a) to a third position, for example, a reverse position R. At this time, the fluid in the first tail chamber 17 is discharged from the second port 9, and the fluid in the second tail chamber 23 is discharged from the second port 9 via the second communication passage 11.

In addition, in the previous embodiment, the first, second, and third positions were neutral, forward, and reverse positions N, F, and R.
The position is not limited to this, and may be, for example, a first speed, second speed, or third speed position.

(Effects of the invention) As described above, according to the present invention, the following excellent effects can be achieved.

(1) Since it has a composite structure, the overall length can be shortened.

(2) Since there are only two ports, the structure of the accompanying manual control valve can be simple, and the piping with it can also be simplified.

As a result, costs are reduced.

(3) Since the second and third positions are obtained before and after the first position, this can be applied as is when operating a manual control valve for forward and backward movement of the transmission.

(4) Since the second and third positions can be obtained before and after the first position, and the first position can be obtained without supplying pressure fluid to the two ports, abnormal situations may occur. It is maintained in the first position even if no pressure fluid can be sent.

Therefore, when the first position is set to the neutral position, it is reliably maintained at the neutral position, so safety is high.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first position of a three-position hydraulic cylinder according to an embodiment of the present invention. FIG. 2 is a similar view showing a second position. FIG. 3 is a similar view showing the third position. FIG. 4 is a schematic diagram showing the first position of a conventional three-position hydraulic cylinder. FIG. 5 is a similar view showing the second position. FIG. 6 is a similar view showing the third position. 1... Three-position fluid pressure cylinder, 2... Cylinder body, 3... Movable cylinder, 4... Piston,
5... Piston rod, 6... First elastic body, 7...
...Second elastic body, 8...First port, 9...Second port, 10...First continuous passage, 11...Second communication passage.

Claims (1)

[Scope of utility model registration request] A cylinder body is provided with a first cylinder cavity therein, and a first rod chamber and a first tail chamber are formed before and after the first cylinder cavity of the cylinder body. A movable cylinder with two cylinder cavities, a piston slidably fitted so that a second rod chamber and a second tail chamber are formed before and after the second cylinder cavity of the movable cylinder, a cylinder body and a movable cylinder. a piston rod that slidably penetrates the front portion of each of the piston rods and whose rear end is connected to the piston; a first elastic body that is interposed between the cylinder body and the movable cylinder and biases the movable cylinder rearward; a second elastic body interposed between the movable cylinder and the piston and urging the piston forward; a first port provided in the cylinder body and communicating with the first rod chamber; and a first elastic body provided in the cylinder body and communicating with the first rod chamber. a second port communicating with the tail chamber; a first communication passage provided in the movable cylinder that communicates the first port and the second rod chamber; and a first communication passage provided in the movable cylinder that communicates the second port with the second tail chamber. A double passage and
A three-position fluid pressure cylinder characterized by comprising: