JP2534918Y2 - Check ball control rod for hydraulic cylinder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check ball control rod for controlling movement of a check ball built in a hydraulic cylinder.

[0002]

2. Description of the Related Art Conventionally, as this type of check ball control rod, as shown in FIG. 3, a groove-shaped check ball control rod a in which a recess b1 is formed in the middle of a sliding portion b is used. The sealing is achieved by incorporating an O-ring into the recess b1.

[0003]

However, in the structure of the sliding portion b of the above-mentioned conventional check ball control rod a, it is difficult to plate the surface because of the unevenness, and the plating is difficult. Even if it does, plating burrs are likely to occur at the corner b2 of the sliding portion b. For this reason, the corner portion b2 of the sliding portion b is apt to be bitten, and therefore, abrasion powder is easily generated, and this abrasion powder prevents smooth sliding of the check ball control rod a and causes a problem of deteriorating the sealing performance. there were.

[0004]

The check ball control rod of the hydraulic cylinder of the present invention is slidably provided in the hydraulic cylinder, and forcibly moves the check ball built in the hydraulic cylinder to supply hydraulic pressure. In a check ball control rod for controlling the expansion and contraction of the telescopic rod by changing a path, the check ball control rod has a rod-shaped rod main body having a larger diameter and a straight-shaped sliding portion than the rod main body. A hydraulic cylinder in which a sliding portion slides through a sliding hole formed in a hydraulic cylinder body, plating is applied to a peripheral surface of the sliding portion, and a sliding portion of the check ball control rod is disposed. A seal is provided in the middle of the sliding hole on the main body side so that the sliding portion slides and covers the outer surface of the hydraulic cylinder main body from the outside of the seal. In which over it has been interposed.

[0005]

[Function] By forming the sliding part of the check ball control rod in a straight shape, plating is easy, and since there is no uneven part on the sliding part, it can be finished fine without burrs when plated. Can be. In addition, a seal is provided outside the sliding part (sliding hole of the hydraulic cylinder main body) whose strength has been increased by plating, and a collar is arranged from the outside of the seal to the outer surface of the hydraulic cylinder main body. The portion where the sliding portion comes into sliding contact with only the oil side inside the hydraulic cylinder main body from the seal excluding the seal and the collar, and this oil serves as a lubricant to smoothly slide the two.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a hydraulic cylinder.

In this hydraulic cylinder, main bodies 11 and 21 are fixedly mounted such that rods 12 and 22 of two first and second hydraulic cylinders 10 and 20 expand and contract in directions opposite to each other.

The first hydraulic cylinder 10 includes the main body 11
, A rod 12, and a piston portion 12a provided at a base end of the rod 12.

The rod 12 has passages 13 and 14 formed in the center and the outer periphery thereof, and the passages 13 and 14 are provided with hydraulic pumps and switching valves (not shown). Pressure oil is supplied from the section.

The passage 13 is inserted into the piston chamber 1 through passages 16a, 16b and 16c formed at the base end of the main body 11 within an insertion member 15 slidably inserted into the passage 13.
7 is connected. The passage 14 communicates with a rod chamber 19 via a communication portion 18.

A first check valve 30 and a second check valve 40 are arranged in the passages 16a, 16b, 16c.

As shown in FIGS. 1 and 2, the check valve 30 includes a valve body 31 and a check ball 32 provided at one end of the valve body 31 and pressed against a valve seat 101 formed on the first hydraulic cylinder 10. It is composed of The check valve 30 is provided with a check ball 32 by a spring 35.
Are urged to press against the valve seat 101.

The other end of the valve main body 31 is inserted and locked in the fitting member 15, and when the rod 12 extends substantially to its maximum, the piston portion 12a moves the fitting member 15 in the extending direction (FIG. 2). (In the direction of arrow P shown in FIG. 3), the check ball 32 is detached from the valve seat 101 against the urging force of the spring 35, and thus the check ball 32 is moved into the passage 16 a and the piston chamber 25 of the second hydraulic cylinder 20. The communicating passage 102 communicates with the passage 102.

The valve body 31 and the check ball 32 are directly joined by welding. Specifically, the valve body 31 and the check ball 32 are directly joined by pressure welding, and the valve body 31 and the check ball 32 are directly joined by projection welding.

The second check valve 40 is such that the check ball 41 is pressed against the valve seat 103 by the urging force of the spring 42 and is provided at the rod end of the second hydraulic cylinder 20 when the second hydraulic cylinder 20 is retracted. The check ball 41 is pressed against the urging force of the spring 42 from the valve seat 103 by forcibly sliding a check ball control rod (hereinafter, simply referred to as a rod) 43 in the arrow P direction by the pressing member 50. It is configured to be detached.

The rod 43 has a rod-shaped rod body and a sliding portion 43a having a diameter larger than that of the rod body and having a straight shape.
Is formed, and this straight-shaped sliding portion 43a is formed.
Is plated on the periphery.

A sliding hole 11a in which the sliding portion 43a slides is formed on the main body 11 side where the sliding portion 43a of the rod 43 is disposed, and a collar 110 is formed in the sliding hole 11a. And a penta seal 111 are provided.
The collar 110 and the penta-seal 111 have a penta-seal 111 interposed in the middle of the sliding hole 11a, and a main body 11 from the outside of the penta-seal 111.
The collar 110 is interposed over the surface of the sliding member 43, and the inner peripheral surfaces of the collar 110 and the penta seal 111 are in sliding contact with the peripheral surface of the sliding portion 43a.

As described above, the second hydraulic cylinder 20 comprises a main body 21, a rod 22, and a piston portion 23 provided at a base end of the rod 22,
The piston chamber 25 is connected to the passage 102 of the first hydraulic cylinder 10 by a pipe (not shown), and the rod chamber 26 is connected to the passage 14 of the first hydraulic cylinder by a pipe (not shown).

Next, the first and second hydraulic cylinders 1
The operations at 0 and 20 will be briefly described.

First, when pressure oil is supplied to the passage 13 of the first hydraulic cylinder 10 in a state where the first and second hydraulic cylinders 10 and 20 are retracted as shown in FIG. It is supplied to the piston chamber 17 of the first hydraulic cylinder 10 via the passages 16a, 16b, 16c, and extends the rod 12 of the first hydraulic cylinder 10. When the rod 12 extends to the maximum, the first check valve 30 is opened by the piston portion 12a pulling the insertion member 15 in the extending direction, and the pressure oil passes through the passage 102 to the piston of the second hydraulic cylinder 20. It is supplied to the chamber 25 and the rod 22 of the second hydraulic cylinder 20 extends. When the second hydraulic cylinder 20 is extended, the second check valve 40
c, thereby closing the first hydraulic cylinder 10 in the extended state.

Further, at the time of contraction, by supplying the pressure oil to the passage 14 of the first hydraulic cylinder 10, this pressure oil is supplied to the rod chamber 26 of the second hydraulic cylinder 20 via a pipe (not shown). The second hydraulic cylinder 20 retracts. At this time, the oil on the piston chamber 25 side of the second hydraulic cylinder 20 is supplied to the pipe, the passage 102 of the first hydraulic cylinder 10,
The oil is returned to the oil reservoir (not shown) through the opened first check valve 30, the passage 16a, and the passage 13.

When the second hydraulic cylinder 20 finishes retracting, the pressing member 50 provided at the rod end of the second hydraulic cylinder 20 comes into contact with the rod 43 of the first hydraulic cylinder 10 and the rod 43 Is forcibly slid in the direction of arrow P, and the second check valve 40 is opened by the sliding of the rod 43. When the second check valve 40 is opened, the oil on the piston chamber 17 side of the first hydraulic cylinder 10 is supplied with pressure oil to the passage 14 of the first hydraulic cylinder 10, and the passages 16 c, 16 b, 16 a, 13 a Through the first hydraulic cylinder 10
Degenerate. That is, the first check valve 30 and the second check valve 40 sequentially retract from the second hydraulic cylinder 20.

This hydraulic cylinder is applied, for example, as a telescopic actuator of a three-stage multi-stage boom composed of a base end boom, an intermediate boom and a distal end boom.

More specifically, the rod end of the first hydraulic cylinder 10 is fixed to a base end boom (not shown), and the main bodies 11 and 21 of the first hydraulic cylinder 10 and the second hydraulic cylinder 20 are fixed to an intermediate boom (not shown). Further, the rod end of the second hydraulic cylinder 20 is fixed to a tip boom (not shown). As a result, at the time of extension, the intermediate boom and the tip boom are sequentially extended, and at the time of contraction, the tip boom and the intermediate boom are sequentially contracted.

[0026]

As described above, according to the present invention, since the sliding portion of the check ball control rod is formed in a straight shape, plating can be easily performed, and the sliding portion has no irregularities. It is possible to finish finely without generating burrs when plating is performed, and to smoothly slide the check ball control rod. In addition, a seal is provided outside the sliding part (sliding hole of the hydraulic cylinder main body) whose strength has been increased by plating, and a collar is arranged from the outside of the seal to the outer surface of the hydraulic cylinder main body. The portion where the sliding portion comes into sliding contact is only on the oil side inside the hydraulic cylinder main body from the seal excluding the seal and the collar, and this oil acts as a lubricant to smoothly slide both parts. Even if the moving hole side is damaged by abrasion powder, etc., the plated strong sliding part will not be damaged, so the sealability can be improved without damaging the seal and oil leakage will occur There is no.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a check ball control rod of a hydraulic cylinder according to the present invention.

FIG. 2 is an enlarged sectional view showing a check ball control rod of the hydraulic cylinder according to the present invention.

FIG. 3 is a side view showing a conventional check ball control rod.

[Explanation of symbols]

 11 Main body of first hydraulic cylinder 11a Sliding hole 41 Check ball 43 Check ball control rod 43a Sliding part 110 Collar 111 Penta seal

Claims (1)

(57) [Scope of request for utility model registration] 1. A hydraulic cylinder, which is slidably provided in a hydraulic cylinder,
A check ball control rod for controlling the expansion and contraction of the telescopic rod by forcibly moving a check ball built in the hydraulic cylinder to change a hydraulic supply path, wherein the check ball control rod is a rod-shaped rod body.
Sliding part with a larger diameter and a straight shape than the rod body
Is formed, and the sliding portion is formed on the hydraulic cylinder body.
With slides sliding hole, it is plated on the peripheral surface of the sliding portion, also in the middle portion of the sliding hole of the hydraulic cylinder body side of the sliding portion is disposed in the check ball control rod A seal with which the sliding part slides is interposed and
From the outside of the seal to the outer surface of the hydraulic cylinder body
A check ball control rod for a hydraulic cylinder, wherein a collar is interposed .