KR100231069B1 - Synchronizing apparatus for hydraulic cylinder - Google Patents

Abstract

The present invention reliably realizes the synchronization lowering of a plurality of hydraulic cylinders with a simple configuration.

The synchronizer cylinder 5 in the tuning device 4 according to the present invention is composed of a cylinder tube 7 and a flanger 9 having a piston 8, which moves forward and backward in the axial direction. The first pressure oil chamber 10 is formed on the rear surface of (8), the second pressure oil chamber 11 is formed on the front surface of the piston 8, and the third pressure oil chamber 12 is formed on the front side of the flanger 9, respectively. In addition, in the third pressure oil chamber 12, the fixed flanger 14 protrudes from the front surface of the third pressure oil chamber 12 toward the flanger 9, and the end of the fixed flanger 14 is the front surface of the flanger 9. It penetrates through and protrudes into the 4th pressure oil chamber 13 inside. The pressure oil passage 19 provided in the fixed plunger 14 is connected to the hydraulic unit 30.

Description

Synchronization device of hydraulic cylinder {SYNCHRONIZING APPARATUS FOR HYDRAULIC CYLINDER}

The present invention relates to a tuning device which is installed in a hydraulic circuit using a plurality of hydraulic cylinders, such as an automobile maintenance lift, and which drives each of the hydraulic cylinders in synchronization.

For example, in a hydraulic circuit such as a car maintenance lift that lifts a car by a pair of lifts each equipped with a hydraulic cylinder, the synchronization between both hydraulic cylinders and the hydraulic source is performed so that a step is not generated in the left and right lifts due to the unloading of the vehicle. A tuning device is provided through a cylinder. This is provided with at least one piston part in a flanger or a rod that is driven by the hydraulic oil supply from the hydraulic source, and at the front of the piston part or the flanger to form a pressure oil chamber of the same cross-sectional area, respectively. When the flanger and the like are driven by being connected to the hydraulic cylinder, the same amount of hydraulic oil is sent from the hydraulic chambers to the corresponding hydraulic cylinders so that the hydraulic cylinders can be synchronized.

On the other hand, the lowering of the lift (double acting of the hydraulic cylinder and the synchronizer cylinder) is often dependent on the external force applied to the hydraulic cylinder by a load or the like, and when the external force is small or absent, the resistance inside the synchronizer cylinder is The operability deteriorates and the lift operation is very slow or does not descend at all on the lift side. In this case, as a mechanism for forcibly lowering in this case, in Japanese Patent Application Laid-Open No. 55-140804 or 61-104804, another cylinder is installed outside the synchronizer cylinder to connect rods of both cylinders. Disclosed is a configuration in which the rod of the synchronizer cylinder is doubled by driving. Therefore, according to these constitutions, smooth double acting of the synchronizer cylinder (forced drop) is obtained, while the synchronizer cylinder assembly is enlarged due to the adoption of an external cylinder, which leads to an increase in cost, and also to the layout of the cylinder size or hydraulic unit. Restricted In addition, since the rod is exposed to the outside, dust and air may be easily mixed, which may cause deterioration of performance such as durability and operability.

On the other hand, in the case of a fixed-cost lift, even if the synchronizer cylinder is employed, the hydraulic cylinders on the left and right side do not synchronize with each other due to oil leakage, and cause both sides of the lift due to the inclination between the lifts or the failure to reach the stroke end. However, to correct this, it is very cumbersome to lift the lift to the maximum, either manually or automatically.

Therefore, the first embodiment of the present invention described in claim 1 can reliably perform the double acting operation of the synchronizer cylinder, as well as the rational configuration of the hydraulic cylinder which suppresses the increase in cost and does not affect the setting of the cylinder size. The purpose is to provide a tuning device for.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory view of a synchronizing device for a hydraulic cylinder installed in a car maintenance lift.

(Explanation of symbols for the main parts of the drawing)

1a, 1b: Lifter 2a, 2b: X-type telescopic mechanism

3a, 3b: hydraulic cylinder 4: synchronizing device

5: Synchronize cylinder 7: Cylinder tube

8: piston 9: flanger

10: first pressure chamber 11: second pressure chamber

12: third pressure chamber 13: fourth pressure chamber

14: fixed flange 15: first pipe

16: Route 2 Route 17: Route 3

18: 4th line 20: 1st correction valve

21: 2nd correction valve 22: 3rd correction valve

23: fourth compensation valve 30: hydraulic unit

31: oil tank 33: pump

34: switching valve

In order to achieve the above object, the invention as set forth in claim 1 is characterized in that a double-acting mechanism is provided in the synchronizer cylinder for supplying hydraulic pressure in the double-acting direction by supplying pressure oil from the hydraulic source. will be.

In addition to the object of the invention described in claim 1, the invention described in claim 2 includes a double-acting pressure oil chamber formed in the flanger and a flow path connected to the hydraulic source in order to easily configure the double acting mechanism. At the same time, it is a fixed plunger which protrudes toward the double acting side in the pressure oil chamber on the side of the flanger reciprocating side, and is coaxially fitted to the flanger so as to communicate the flow path with the double acting oil chamber.

In addition to the object of the invention as claimed in claim 1 or 2, the invention described in claim 3 further comprises: each of the hydraulic oil chambers at predetermined reciprocating positions of the flanger in the synchronizer cylinder in order to effectively cope with the hydraulic cylinder misalignment due to the oil leakage or the like. Is connected to each other, and the correction pipe which equilibrates and equalizes the flow volume of each pressure oil chamber by a suitable quantity is provided.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, the Example which applied this invention to the automobile fixed cost lift is demonstrated based on drawing for example.

As shown in Fig. 1, the vehicle maintenance lift includes two left and right lifters 1a and 1b, and the lifting tables of the lifters 1a and 1b are supported by the X-type expansion and contraction mechanisms 2a and 2b, respectively. At the same time it is driven by the hydraulic cylinder (3a, 3b). Both hydraulic cylinders 3a and 3b are assembled to a synchronizing device 4 composed of the synchronizer cylinder 5 and the hydraulic unit 30, connected in parallel, and are supplied with hydraulic pressure by supplying pressure oil from the hydraulic unit 30. The cylinders 3a and 3b are stretched and expanded in synchronization with the synchronizer cylinder 5, and the lifters 1a and 1b on the left and right are moved up and down.

In addition, the synchronizer cylinder 5 penetrates the cylinder tube 7 formed with a pressure oil chamber having a small diameter on the right side and a large diameter on the left side with the partition 6 provided at the center in the center thereof, and the partition 6 through the partition wall 6. It consists of a flanger 9 which can move back and forth in the axial direction and has a piston 8 at its rear end (left side of the figure). The flanger 9 is in sliding contact with the pressure chamber on the small diameter side of the cylinder tube 7 and the inner hole of the partition wall 6, while the rear piston 8 is the oil pressure chamber on the large diameter side of the cylinder tube 7. The first pressure oil chamber 10 on the rear surface of the piston 8 and the second pressure oil chamber 11 on the front surface of the piston 8 on the large diameter side of the cylinder tube 7. And in the small diameter side, the 3rd pressure oil chamber 12 is formed in front of the flanger 9, respectively. Moreover, in the 3rd pressure oil chamber 12, the fixed flanger 14 coaxial with the flanger 9 protrudes from the front surface of the 3rd pressure oil chamber 12 toward the flanger 9, and this fixed flanger 14 is provided. The tip of the penetrates through the front surface of the flanger 9 and protrudes into the fourth pressure oil chamber 13 formed in the flanger 9.

Here, the dimensional relationship between each hydraulic oil chamber is demonstrated. Here, the cross-sectional area of the second pressure oil chamber 11 and the cross-sectional area of the third pressure oil chamber 12 are set to be the same. Therefore, the diameter of the second pressure oil chamber 11 is d ₁ , the diameter of the flanger 9 is d ₂ , the diameter of the fixed flanger 14 is d ₃ , and the cross-sectional area of the first pressure oil chamber 10 is A ₀ ,. When the cross-sectional area of the second pressure oil chamber 11 is A ₁ , the cross-sectional area of the third pressure oil chamber 12 is A ₂ , and the cross-sectional area of the fixed flanger 14 is A ₃ ,

Becomes Therefore, A ₀ = A ₁ + A ₂ + A ₃ , but the relationship A ₀ = 2A ₁ + A ₃ is obtained by setting A ₁ = A ₂ . Here again

You may also

On the other hand, on the large diameter side of the cylinder tube 7, the inlet and outlet 10a of the hydraulic oil to the first pressure oil chamber 10 is the pressure oil supply pipe 32 and the return pipe of the hydraulic unit 30 by the first pipe line 15. The outlets 11a of the pressurized oil to the second pressure oil chamber 11 are connected to the hydraulic cylinder 3a by the second pipe line 16, respectively. On the smaller diameter side, the entrance / exit 12a of the hydraulic oil to the third pressure oil chamber 12 is connected to the hydraulic cylinder 3b by the third pipe 17, and is provided inside the fixed flange 14. A pressure oil passage 19 serving as an outlet for pressure oil to the four pressure oil chamber 13 is connected to the switching valve 34 of the hydraulic unit 30 by the fourth pipe passage 18. In addition, on the larger diameter side of the cylinder tube 7, the valve is closed in a normal state, and the first correction valve 20 and the second correction valve 21 which open the valve by contact with the piston 8 are provided, respectively. The third correction valve 22 and the fourth correction valve 23 which are closed in the normal state on the small diameter side and open the valve by contact with the flanger 9 are provided, respectively. Here, the first correction valve 20 and the third correction valve 22 are connected to each other by a correction pipe 24, but the correction pipe 24 is communicated with the second pipe 16 in an intersecting manner. In addition, the second correction valve 21 is connected to another inlet 12b installed in the third pressure oil chamber 12 by the correction pipe 25, and the fourth correction valve 23 is connected to the correction pipe 26. Is connected to the pressure oil supply pipe 32 of the hydraulic unit 30.

Moreover, the edge of the connection of the 1st pressure oil chamber 10 in the said 1st pipe line 15 to the entrance 10a of the 1st pressure oil chamber 10 and each of the hydraulic cylinders 3a and 3b in the 2nd, 3rd pipe lines 16 and 17 is carried out. The fuse valves 27, 27, ... are provided respectively to prevent the sudden drop of the hydraulic cylinders 3a and 3b when a rupture or the like of a pipe line occurs.

In addition, safety valves 28 and 28 which function at the time of step correction of the lifters 1a and 1b described later are provided in the second and third pipe passages 16 and 17, respectively. On the other hand, the air extraction valves 29 and 29 are provided in the 2nd and 3rd pressure oil chambers 11 and 12, respectively.

In the hydraulic unit 30, the pump 33, the switching valve 34, and the check valve 35 are provided from the upstream side in the pressure oil supply pipe 32 provided between the first pipe line 15 and the oil tank 31. At the same time, a relief valve 36 is provided between the pump 33 and the switching valve 34. Similarly, the return pipe 37 provided between the first pipe line 15 and the oil tank 31 is provided with a flow control valve 38 and a lowering valve 39 interlocking with the switching valve 34 from the upstream side, respectively. have. In addition, the fourth pipe line 18 is connected to the oil tank 31 via the switching valve 34.

Next, operation | movement of the tuning device 4 comprised as mentioned above is demonstrated. First, when the pump 33 is driven at the time of ascending, the hydraulic oil is supplied from the first pipe line 15 to the first pressure oil chamber 10 via the switching valve 34 and the check valve 35 in the position of FIG. Push 9) forward. As a result, the volume of the second pressure oil chamber 11 and the third pressure oil chamber 12 is narrowed, so that the working oil of the second pressure oil chamber 11 flows from the entrance 11a to the second pipe 16 and the hydraulic cylinder 3a. The hydraulic oil in the third pressure oil chamber 12 flows from the entrance 12a to the third pipe 17 and is sent to the hydraulic cylinder 3b. Since the cross-sectional areas of the second pressure oil chamber 11 and the third pressure oil chamber 12 are the same, the hydraulic cylinders 3a and 3b having the same flow rate operate in synchronization, and both lifters 1a and 1b move in the same manner. To rise.

On the other hand, at the time of lowering, the switching valve 34 and the lowering valve 39 are simultaneously switched to the lowering side, so that the hydraulic oil passes from the fourth conduit 18 through the hydraulic oil passage 19 in the fixed plunger 14 to the fourth pressure oil chamber 13. ), The force of the cross-sectional area x hydraulic pressure of the pressure oil passage 19 acts on the flanger 9. In addition, the hydraulic pressure applied to the hydraulic cylinders 3a and 3b by the load is passed through the second pressure oil chamber 11 from the second pipe line 16 and through the third pressure oil chamber 12 from the third pipe line 17, respectively. Since it acts on (8) and the flanger 9, the piston 8 is retracted by the force of both. In addition, the hydraulic oil of the first pressure oil chamber 10 is returned to the oil tank 31 through the return pipe 37 from the first pipe line 15 by switching of the lowering valve 39, but at this time, the flow control valve 38 As a result, since the flow rate flowing through the return pipe 37 is constant, the descending speeds of the lifters 1a and 1b do not change even if the loads applied to the lifters 1a and 1b vary. Of course, even if the load applied to both lifters 1a and 1b is 0, the descending speed will not be slowed down by the pressure oil sent from the oil pressure passage 19 to the 4th oil pressure chamber 13.

In this regard, when the initial setting, that is, when the lifters 1a and 1b are operated for the first time, air enters the second pressure chamber 11 and the third pressure chamber 12, so that the vehicle is first lifted to the lifters 1a and 1b. The lift operation is performed without raising the back. Then, the flanger 9 reaches the most advanced position, and since the third and fourth correction valves 22 and 23 are opened, respectively, the pressure oil from the pump 33 passes through the correction pipe 26 to the fourth correction valve. It is sent from 23 to the 3rd pressure oil chamber 12, and is sent from the 3rd pipe line 17 to the hydraulic cylinder 3b, and raises the lifter 1b. At the same time, the pressure oil of the third pressure oil chamber 12 is sent to the second pressure oil chamber 11 and the hydraulic cylinder 3a through the third correction valve 22, the correction pipeline 24, the second pipeline 16, Raise the lifter 1a. Here, the air in the second and third pressure oil chambers 11 and 12 is completely drawn out and filled with the hydraulic oil when the air is lifted and lowered several times while extracting the air by the air extraction valves 29 and 29. In addition, when the air in the fourth pressure oil chamber 13 rises, it is sent from the pressure oil passage 19 to the oil tank 31 through the fourth pipe line 18 and the switching valve 34, and is discharged to the atmosphere. Repeat the air draw to complete.

As described above, in the tuning device 4, the hydraulic cylinders 3a and 3b are lowered by adopting a double acting mechanism such as the fourth pressure oil chamber 13 or the fixed plunger 14 to the flanger 9 of the synchronizer cylinder 5. The operation can be reliably performed at a constant speed regardless of the presence or absence of a load and the magnitude of the load. Of course, even if the viscosity of the oil rises at low temperatures, there is no effect on the falling speed. In addition, by using the synchronizing mechanism 5 in the synchronizer cylinder 5 without using an external cylinder or the like,

(1) Since the hydraulic cylinders 3a and 3b can also be used in a single acting structure, only one oil pressure piping to the hydraulic cylinders 3a and 3b is required, resulting in a compact and simple hydraulic circuit and low cost.

(2) Since the double acting mechanism is constructed by using internal parts such as the flanger (9), the miniaturization and weight reduction of the synchronizer cylinder (5) can be achieved, and the increase in cost is suppressed and the occurrence of failure is reduced, resulting in high reliability. Obtained. In addition, the sliding portion is not limited to the increase of one place by the fixed plunger 14, and the internal resistance loss can be minimized.

③ Because there is no contact with outside air, there is no mixing of dust or air, there is no fear of contaminating hydraulic oil or leakage of hydraulic oil, so it can be expected to improve the operation and durability.

(4) Since there are few sliding parts, and the sliding part (fixed plunger 14) of forced descending is a free supporting structure, there are two places requiring substantially precision, which is advantageous in terms of cost and stability of performance.

⑤ Since the hydraulic pressure applied to the sealing of the sliding part is not the size of the load of the hydraulic cylinders 3a and 3b, but the difference between the loads, the burden on the sealing packing is less, and the life of the battery can be extended and the safety can be secured. Effect appears.

In particular, in the present embodiment, the above-described dimensional relationship, that is, the cross-sectional area A ₀ > cross-sectional area A ₁ of the first pressure oil chamber A ₁ + cross-sectional area A ₂ of the third pressure oil chamber, and cross-sectional area A ₁ of the second pressure oil chamber From the relation of the cross-sectional area A _{2 of} the three pressure chambers, the secondary hydraulic pressures generated in the second and third pressure chambers 11 and 12 are higher than the primary hydraulic pressure applied to the first pressure chamber 10 (increasing pressure). The thrust generated at 3a and 3b becomes even stronger. In other words, compared with obtaining the same thrust, the hydraulic cylinders 3a and 3b of the present embodiment can be formed more thinly, and further lowering of the lifters 1a and 1b can be achieved. do.

According to the above-described dimensional relationship, the area ratio between the oil pressure chambers is large, and the oil pressure of the second, third pipe lines 11 and 12 and the first pressure oil chamber 10 at the time of lowering is suppressed to be lowered. The compression repulsion of the pressurized oil at the time of stopping becomes small, and the effect which can make the jumping shock of the lifters 1a and 1b small can be obtained. On the other hand, X-type expansion and contraction mechanism (2a, 2b) is usually equipped with a fall prevention safety device such as a rack and a stop pawl, but, for example, even if the descent operation in the stop state between the stop pawl and the rack, extra safety device Since no force is applied, there is no need to give extra strength to the lifter side. Therefore, it is possible to prevent the increase in cost, which leads to the lowering of the lifter.

In this embodiment, further characteristic corrections will be described on a case-by-case basis.

Correction 1 [When both or one side of the 2nd and 3rd pressure oil chambers 11 and 12 decreases, and both lifters 1a and 1b generate both ends or steps |

In the case of correcting to the upper limit first, when both lifters 1a and 1b are lifted up and the flanger 9 is moved to the foremost position, the flanger 9 contacts the third and fourth correction valves 22 and 23. Open the valve for both calibration valves. If the rising operation is continued as it is, it is not sent to the first pressure oil chamber 10 in which the pressure oil is full, but is sent to the third pressure oil chamber 12 via the correction pipe 26 and the fourth correction valve 23. Lose. The pressure oil of the third pressure oil chamber 12 is sent from the entrance 12a and the third pipe 17 to the hydraulic cylinder 3b, and at the same time, the correction pipe 24 and the second pipe from the third compensation valve 22. From 16, it is sent also to the hydraulic cylinder 3a. Therefore, even if the flanger 9 stops, both hydraulic cylinders 3a and 3b operate up to the stroke end, and the hydraulic oil becomes full, and the level difference of both lifters 1a and 1b is corrected.

Calibration 2

In the same case as in the correction 1, when correcting at the lower limit, when the lowering operation is performed to move the flanger 9 to the rearmost retracted position, the piston 8 contacts the first and second correction valves 20 and 21, Open both calibration valves. If the lowering operation is continued as it is, both the lifters 1a and 1b and the hydraulic cylinders 3a and 3b reach the lower limit, respectively, and the return of the hydraulic oil from the hydraulic cylinders 3a and 3b is eliminated. The three pressure oil chambers 11 and 12 are in a vacuum state. At this time, since the lower valve 39 is also open, the hydraulic oil of the oil tank 31 enters the first pressure oil chamber 10 from the return pipe 37 through the first pipe line 15, and then again the first correction valve ( 20 is sent to the second pressure oil chamber 11 by atmospheric pressure via the correction pipe 24 and the second pipe 16. Similarly, the hydraulic oil which entered the 1st pressure oil chamber 10 is sent to atmospheric pressure by the atmospheric pressure to the 3rd pressure oil chamber 12 via the 2nd correction valve 21, the correction line 25, and the entrance and exit 12b. Therefore, both the 2nd and 3rd pressure oil chambers 11 and 12 are filled with hydraulic fluid, and the level | step difference of the lifter 1a, 1b is correct | amended.

Correction 3 [When the oil pressure of one or both of the second and third pressure oil chambers 11 and 12 increases, and a step or the lower limit is not reached in the lifters 1a and 1b]

First, when correcting at the upper limit, the lift operation is performed and operated until either one of the lifters 1a and 1b reaches the upper limit. At this time, the flanger 9 does not reach the most advanced position. When the lifter 1b first reaches the upper limit, the hydraulic pressure in the third pressure oil chamber 12 is increased to about twice the maximum hydraulic pressure generated by the pump 33. Then, the third correction valve 22 acts as a relief valve, opens the valve, sends pressure oil from the correction pipe 24 and the second pipe 16 to the hydraulic cylinder 3a on the lifter 1a side, and lifts the lifter ( Raise 1a) to the upper limit. At the same time, the safety valve 28 connected to the third conduit 17 also operates to reduce the hydraulic pressure in the copper conduit 17. Therefore, the pressure balance between the second and third pressure oil chambers 11 and 12 is taken to prevent the occurrence of abnormal high pressures and at the same time correct the level difference. Thereafter, the pressurized oil from the pump 33 is only refluxed between the pressurized oil supply pipe 32 and the return pipe 37 and the oil tank 31.

On the other hand, when the lifter 1a first reaches the upper limit, the hydraulic pressure on the side of the lifter 1a becomes abnormally high due to the pressure-increasing effect as described above, but in this case, the safety valve 28 connected to the second pipe line 16 is provided. As a result, the abnormal high pressure can be opened, and damage prevention and step correction of the apparatus can be performed.

Calibration 4

In the same case as in the correction 3, when correcting at the lower limit, the lowering operation is first performed to move the flanger 9 to the last retracted position. At this time, the lifters 1a and 1b do not all reach the lower limit position. However, the piston (8) is the hydraulic cylinder (3a) by the hydraulic pressure generated in both hydraulic cylinders (3a, 3b) by the weight of the lifters (1a, 1b) to open the first and second correction valves (20, 21) valves. The hydraulic fluid of the oil tank (2) is supplied from the return pipe (37) via the second pipe (16), the correction pipe (24), the first compensation valve (20), the first pressure oil chamber (10), the first pipe (15). 31). Similarly, the hydraulic oil of the hydraulic cylinder 3b is connected to the third pipe 17, the third pressure oil chamber 12, the correction pipe 25, the second compensation valve 21, the first pressure oil chamber 10, and the first pipe ( 15 is discharged from the return pipe 37 to the oil tank 31 via. Therefore, both lifters 1a and 1b can be lowered to the lower limit, thereby eliminating the step difference.

Thus, according to this embodiment, step correction of the lifters 1a and 1b and unreasonable upper and lower limits are possible regardless of the upper and lower positions of the lifters 1a and 1b. In particular, since it is a configuration that is corrected by only a simple up or down operation, the user can obtain a good convenience of use by automatically eliminating the step during use of the lifter without performing a special operation for correction.

In addition, the step between the lifters, such as the case may occur due to the flow rate in the oil pressure chamber, the case that the lifting platform touches the obstacle during the lifter lowering, or the lowering of only one side is prevented. However, in the present embodiment, the pressure difference between hydraulic cylinders is simpler than the conventional method of forcibly lowering the hydraulic cylinder on the opposite side of the hydraulic cylinder. Therefore, when the sensor for detecting the differential pressure is inserted, the left and right step detection can be easily performed. In this case, the occurrence of a step can be prevented in advance.

In addition, in the above embodiment, a hydraulic oil chamber is installed at the front of the piston and the front of the flanger by using a flanger provided with one piston, and the two hydraulic cylinders connected to each other have been described. A double acting mechanism is adopted by a fixed plunger in the same manner as above, in which a plurality of hydraulic cylinders having the same cross-sectional area are formed between the respective pistons and the hydraulic chambers are connected to hydraulic cylinders to synchronize three or more hydraulic cylinders. Is possible.

According to the invention described in claim 1, by providing the double acting mechanism inside the synchronizer cylinder, the lowering operation of the hydraulic cylinder can be reliably performed at a constant speed regardless of the presence or absence of a load and the magnitude of the load. Of course, even if the viscosity of the oil rises at low temperatures, there is no effect on the falling speed. In particular, since the hydraulic cylinder can be used as a single acting structure, only one oil pressure piping to the hydraulic cylinder is required, and the hydraulic circuit is compact and simple, and low cost is achieved. In addition, the miniaturization and weight reduction of the synchronizer cylinder can be achieved, the increase in cost is suppressed, and the occurrence of failure is reduced, resulting in high reliability. In addition, the layout of the hydraulic unit can be easily performed without being restricted by the installation direction or positioning, and the entire circuit can be miniaturized. In addition, since there is no part which touches the outside air, there is no mixing of dust and air, so it is expected to improve the operation and durability.

Moreover, according to invention of Claim 2, in addition to the effect of Claim 1 invention, the said double acting mechanism can be comprised easily, and cost increase can be suppressed further.

According to the invention described in claim 3, in addition to the effects of the invention of claim 1 or 2, the flow rate between the oil pressure chambers is different due to the oil leakage, etc., due to the adoption of a correction pipe, and the hydraulic cylinder is not misaligned or not reached the stroke end. Even if this occurs, this can be corrected effectively to maintain proper reciprocating operation of the hydraulic cylinder. In particular, since the correction is performed at a predetermined reciprocating position of the flanger, the correction is automatically performed by the normal use of the hydraulic cylinder without requiring special operation for correction, thereby making it convenient in use.

Claims (3)

At least one piston unit is provided, and a hydraulic oil chamber is formed at the hydraulic side of the piston and the flanger while the flanger is built by the supply of the hydraulic oil from the hydraulic source. A synchronizing device for a hydraulic cylinder provided with a synchronizer cylinder capable of connecting and supplying an equal amount of pressure oil to each of the hydraulic cylinders connected to each of the hydraulic oil chambers by the fluctuation of the flanger. And a double actuating mechanism for imparting oil pressure in the double acting direction to the flanger by supplying pressure oil from the hydraulic source to the inside of the synchronizer cylinder. The method of claim 1, The double-acting mechanism is provided in the oil pressure chamber for the double-acting oil pressure chamber formed in the flanger and the hydraulic source, and in the oil pressure chamber of the flanger side of the flanger side, protrudes toward the double-sided side and is coaxially fitted to the flanger. And a fixed plunger in which said flow path is in communication with said double-acting pressure oil chamber. The method according to claim 1 or 2, And a correction conduit for communicating the respective pressure oil chambers with each other at the predetermined reciprocating position of the flanger to correct the flow rate of each pressure oil chamber to an appropriate amount.

Images