JPS5943359Y2 - Simultaneous telescopic boom extension correction device - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention consists of a multi-stage boom consisting of boom tubes inserted telescopically, with double-acting cylinders arranged between adjacent boom parts, and these double-acting cylinders The extension operation side pressure oil chambers of the cylinders are connected to the flow divider through independent oil passages, and then connected to one port of the directional control valve via a common oil passage, and the contraction operation side pressure oil of the double acting cylinder is connected to the flow divider through independent oil passages. In a simultaneous telescopic boom in which the chambers are connected to other ports of the directional control valve via a common oil path, the difference in the amount of extension between each boom section that occurs when each boom cylinder is extended simultaneously. The present invention relates to an extension amount correction device for a simultaneous telescopic boom, which can obtain a state in which each boom cylinder is extended by the same amount by correcting the amount of extension.

(Prior art) In a simultaneous telescoping boom in which each boom cylinder is extended and retracted simultaneously via a flow divider, correction for the expansion/contraction error that occurs because each boom cylinder does not extend and retract uniformly requires the boom to be fully retracted or fully retracted. It was to be corrected when

An example thereof will be explained based on FIG.

In FIG. 3, reference numerals 40 and 41 indicate double-acting cylinders disposed between adjacent boom sections of a multi-stage boom consisting of three or more boom cylinders fitted telescopically, and these double-acting cylinders 40, 41 reduction operation side pressure oil chamber 40'
, 41' are connected to each other, and these oil chambers are connected to the A port 43 of the directional control valve 43 via the first oil supply/drainage path 42.
'It is connected to the.

In addition, the extension operation side pressure oil chamber 40'' of the double-acting cylinder 40.41
, 41'' are each independently connected to the flow divider and collector 44 via the second supply/discharge circuit 45, and then connected to the B port 43'' of the directional control valve 43.

Reference numerals 46 and 47 indicate branch paths branching from the second supply/discharge circuit 45 between the extension operation side pressure oil chamber 40''. , 50 are arranged so that the oil in the tank 48 can flow into the second supply/discharge circuit 45.

Reference numerals 51 and 52 denote relief valves provided in bypass oil passages 53 and 54 that connect the respective independent second supply/discharge circuits 45 between the extension operation side pressure oil chambers 40'', 41'' and the flow collector 44.

Then, the B boat 43'' of the directional control valve 43 is connected to the pump side and the A port 431 is connected to the tank side, and the double acting cylinder 40
．． If an extension error occurs between the cylinders when the cylinders 41 are simultaneously extended, it is not possible to correct the extension error in the intermediate extension state. When the IJ reaches its maximum extension first, the pressure of the second oil supply/drainage passage 45 on the side which has been extended to the maximum increases and the IJ valve 52 is opened, and the second oil supply/drainage passage 45 on the side which has not yet been extended to its maximum extent increases in pressure. When oil flows into the passage 45, the double-acting cylinder 41 on the delayed side is accelerated and reaches its maximum extension state.

In addition, the A port 43' of the directional control valve 43 is connected to the pump side.
Connect the port 43'' to the tank side and connect the double acting cylinder 40.
41 and when a reduction error occurs in each boom inspection, it is not possible to correct the reduction error in the intermediate extension state, and for example, among the double-acting cylinders 40 and 41, When it first contracts to the maximum, the hydraulic pressure of the second supply/discharge circuit 45 on the side that contracted to the maximum decreases suddenly, and the check valve 47
Since the oil in the tank 48 is sucked up through the branch path 41, seizing does not occur in the flow divider 44, and the double-acting cylinder 41 becomes the most contracted state with a delay.

As mentioned above, with the conventional model, the expansion/contraction error that occurs during boom expansion/contraction operation is corrected when the boom is fully extended or fully retracted, so it can be used with the boom fully extended or fully retracted. There is no particular unreasonableness when doing so.

(Problems to be Solved by the Invention) However, the conventional one had a problem in that it was not possible to correct an extension error that occurred when the boom was in an intermediate extension state.

Then, when the boom is in an intermediate extension state and the inner boom tube is extended more than the outer boom tube, causing an extension error, this extension error is ignored and each boom tube is When a load determined for each boom extension amount is applied to the boom on the assumption that the extension amount is the same, the boom tube located on the inner side may break.

This idea was created by focusing on these conventional problems, and when an error occurs when the boom tube is extended,
It is an object of the present invention to solve the above-mentioned problems by stopping the extension of the boom tube that has a large amount of extension and allowing the boom tube that has a small amount of extension to extend.

(Means for solving the problem) This invention consists of a multi-stage boom consisting of three or more boom tubes inserted in a telescopic manner, and a double-acting cylinder is installed in each of the adjacent booms. The extension operation side pressure oil chambers of the double-acting cylinders are connected to the flow divider through independent oil passages, and then connected to one port of the direction FF51#ll valve through a common oil passage, and the double-acting cylinder In the simultaneous telescopic boom, the contraction operation side pressure oil chambers of each of the double-acting cylinders are connected to other ports of the directional control valve via a common oil passage, and the expansion operation side pressure oil chambers of each of the double-acting cylinders and the flow collector A branch passage connecting each oil passage to a tank is provided in each of the oil passages, and a balance piston type relief valve having a vent circuit is provided in these branch passages, and the vent circuit is provided with a branch passage that connects the oil passage to the tank. - It is characterized by the provision of an on-off valve for opening and closing the valve at any time.

(effect) Regarding correction of errors that occur when the boom tube is extended.

In this case, an IJ IJ-
Open the opening/closing valve of the vent circuit of the IJ IJ-F valve, which is installed in the branch path leading to the extension side pressure oil chamber of the double-acting cylinder with a large amount of expansion, and set the relief setting pressure of the relief valve to zero. .

Then, the oil discharged from the flow collector is returned to the tank via the relief valve, so the double-acting cylinder with a large amount of expansion stops, and the double-acting cylinder with a small amount of expansion expands, so there is an error in the expansion between each double-acting cylinder. is corrected.

(Example) Next, an example of the present invention will be described based on FIGS. 1 and 2.

A is a base boom tube, B is a second boom tube inserted into this boom tube A, and this boom tube B is connected to the boom tube by a double-acting cylinder 1 placed between both boom tubes A and B. It is designed so that it can be moved inside A or out of boom tube A.

C is a third boom tube inserted into the boom tube B, and this boom tube C is moved into the boom tube B by a double-acting cylinder 2 placed between both boom tubes B and C. It is possible to move outside B.

D is a boom tube, and a top boom tube inserted into C. This boom tube is moved into the boom tube C by a double-acting cylinder 30 placed between both boom tubes C and D. It is possible to move outside of C.

And these boom tubes A, B, C, fitted telescopically,
D forms a multistage boom, and the boom tube B and the boom tube C extend and contract simultaneously, and the boom tube extends and contracts independently.

P is a flow collector formed by connecting the main shafts of two gear motors (pumps) Pl and P2, Pl is the extension side pressure oil chamber 1/ of the double-acting cylinder 1, and P2 is the extension side of the double-acting cylinder 2. It is connected to the operating side pressure oil chamber 21 via oil passages 3 and 4, respectively.

5 is a directional control valve, one of the ports of this directional control valve is connected to the flow divider P, and the other port is connected to the reduction operation side pressure oil chamber 1'' of the double-acting cylinders 1, 2, and 30. , 2".

30'' via an oil passage 6.

When this directional control valve 5 is located at the neutral position as shown in the figure, the oil discharged from the pump 7 is returned to the tank 8, and when this directional control valve 5 is switched, the double-acting cylinder 1,
2.30 can be expanded and contracted.

Reference numeral 9 indicates that when the double-acting cylinder 1 extends and reaches the stroke end, if the dividing flow collector P continues to rotate, an abnormally high pressure will be generated in the oil passage 3. To prevent this, the dividing flow collector P is installed. This is a balance piston type relief valve provided in a branch passage 10 of an oil passage 3 between holding valves 23, which will be described later, and has a vent circuit 9/.

Reference numeral 11 indicates that when the double-acting cylinder 2 extends and reaches the stroke end, if the dividing flow collector P continues to rotate, an abnormally high pressure will be generated in the oil passage 4, so in order to prevent this, the dividing flow collector P An oil passage 4 between the holding valve 24 and the holding valve 24 described later.
A balance piston type IJ installed in the branch path 12 of
It is an IJ-F valve and has a vent circuit 111.

These branches 10.12 are IJ IJ-F valve 9.11
The oil passages 13 merge at the latter stage, and this oil passage 13 is connected to the extension operation side pressure oil chamber 30' of the double-acting cylinder 3.

14 is a balanced piston type relief valve provided in this oil passage 13, and has a vent circuit 14/.

15°16.17 are vent circuits 9', 11', and 14, respectively.
It is an on-off valve installed in '.

The on-off valve 11 opens when the double-acting cylinders 1 and 2 are simultaneously controlled to extend or contract.

As a result, the IJ IJ-F set pressure of the IJ-IJ-F valve 14 becomes zero, and the oil that has reached the oil path 13 via the IJ-IJ-F valve 9 and 11 is transferred to the tank 8 via the IJ IJ-F valve 14.
Reflux to.

18 is a check valve provided in the oil passage 3, and 20 is a check valve provided in a branch passage 21 of the oil passage 4.

These check valves 18 and 20 are opened when the oil passages 3 and 4 become negative pressures, respectively, and supply oil from the tank 8 to the oil passages 3 and 4.

22 is an on-off valve that is closed when the double-acting cylinder 30 is contracted independently.

In Figure 1, the vertical lines provided on the sides of boom tubes B and C are determined by the operator to determine the number of vertical lines on boom tube B protruding from boom tube A and the number of vertical lines on boom tube C protruding from boom tube B. The number of vertical lines can be visually checked, and if the numbers match, it can be confirmed that each boom tube is in a state of being extended by the same amount.

It may be electrically confirmed whether the boom tube is in a state where it has been extended by the same amount.

That is, length detectors in the form of cord reels are provided between boom tube A and boom tube B, and between boom tube B and boom tube C, respectively.
The amount of extension of each boom can be determined by changing the resistance value of the potentiometer as the cord is fed out. If a previously known method is used, the amount of extension of each boom can be determined very accurately, although this increases the cost. can.

Furthermore, 23, 24, and 25 are holding valves provided in the oil passages 3, 4, and 13, which allow free flow of oil from the flow concentrator P to the respective extension operation side pressure oil chambers 1', 2', and 30'. Although the flow is allowed, each extension operation side pressure oil chamber 1', 2', 30'
The oil is discharged from the reduction operation side pressure oil chambers 1", 2", respectively.
This is made possible when the hydraulic pressure increases to 30".

Next, the effect will be explained.

Regarding the case where the boom tube is completely retracted into the boom tube C and the boom tube B and the boom tube C are extended and contracted for work.

In this case, the operator uses the method described above to confirm that there is an error between boom tube B and boom tube C. For example, the amount of extension of boom tube B is compared to the amount of extension of boom tube C. If so, the operator places on-off valves 11 and 15 in the open position.

Next, if the direction control valve 5 is controlled in the direction of extension of the double-acting cylinders 1 and 2, the discharged oil from the pump 7 that has passed through the flow collector P and entered the oil path 3 will be transferred through the branch path 10 until the relief setting pressure is zero. In contrast, the oil discharged from the pump I that has come to the oil path 4 flows into the double-acting cylinder 2 because the relief valve 11 is in the closed state. The extension operation side pressure oil chamber 21 is reached, and the double-acting cylinder 2,
In other words, the boom tube C is extended.

The operator checks the extent of extension of the boom tube C, and if there is no difference in the amount of extension between the boom tube C and the boom tube B, the operator returns the direction control valve 5 to the neutral position and returns the on-off valve 15 to the closed position, and the multi-stage boom is activated. is set to a normal extended state.

This embodiment is a four-stage telescopic boom, but if there is no top boom barrel, that is, in the case of a three-stage simultaneous telescopic boom, the oil passage 13 downstream of the relief valves 9 and 11 will be connected directly to the tank 8. Of course, it should be connected to.

Next, the case of extending the top boom barrel will be explained.

In this case, the on-off valve 11 is opened, the on-off valves 15 and 16 are closed, the directional control valve 5 is positioned on the extension side, and the boom tube B
, the boom cylinder C is fully extended.

When both are fully extended, open the on-off valves 15.16, close the on-off valves 1.7, and open the IJ-F valves 9 and 11.
IJ IJ-Close the valve 14 and connect the oil path 3 from the separation collector P.
The oil discharged from the pump 1 that has reached 4° is merged in the oil passage 13 and sent to the extension side pressure oil chamber 30' of the double-acting cylinder 30 to extend the boom barrel.

When reducing the boom length, the on-off valve 22 is closed, the on-off valve 17 is opened, and the directional control valve 5 is operated to close the oil passage 6.
Pour the discharge oil from pump 7 into.

Then, the flow concentrator P does not rotate because the on-off valve 22 is closed, and on the other hand, since the IJ-F valve 14 is open, the hydraulic pressure of the contraction side pressure oil chamber 30'' of the cylinder 30 causes the expansion operation side pressure oil chamber to open. 30/ oil is in oil path 13, IJ IJ-F valve 1
4 to the tank 8, and the double-acting cylinder 3, in other words, the boom barrel is reduced.

Next, let's consider the case where boom tube B and boom tube C are simultaneously reduced.

In this case, after completely contracting the boom barrel as described above, the operator opens the on-off valve 22, closes the on-off valves 15 and 17, closes the relief valves 9 and 11, and then the operator controls the direction. When the valve 5 is operated to send oil discharged from the pump P to the oil passage 6, the double-acting cylinders 1 and 2, in other words, the boom cylinder C and the boom cylinder B are simultaneously contracted.

In the above embodiment, a multi-stage boom consisting of a boom that extends and contracts at the same time and a boom that extends and contracts independently was explained.
The flow dividers P are Pl, P2. P3 may be configured to extend and retract all the booms at the same time.

(Effect) In this invention, the error in the extension amount that occurs in each boom when the boom is in the intermediate extension state is corrected by independently extending the boom cylinder with the small extension amount in this intermediate extension state. This has the effect that error correction is easy.

In addition, this error is corrected by using a relief valve installed to prevent abnormal pressure rise in the oil passage connecting the flow divider and the extension side pressure oil chamber of the double-acting cylinder. The effect is that the configuration is simple.

[Brief explanation of drawings]

FIG. 1 is a side view of a multistage boom, FIG. 2 is a hydraulic circuit diagram of a simultaneous telescopic boom showing an embodiment of the present invention, and FIG. 3 is a hydraulic circuit diagram of a conventional simultaneous telescopic boom. 1.2...Double acting cylinder, i/, 2/...
... Extension operation side pressure oil chamber, P ... Minute flow collector, 5
... Direction control valve, 1", 2" ... Reduction operation side pressure oil chamber, 1 ... Pump, 3, 4 ...
... Oil passage, 3, 11 ... Relief valve, 9', 1
1'... Vent circuit, 15, 16...
Open/close valve.

Claims (1)

[Claim for Utility Model Registration] A multi-stage boom consisting of three or more boom cylinders fitted in a telescopic manner has double-acting cylinders arranged between adjacent boom parts, and pressure oil on the extension side of these double-acting cylinders. The chambers are connected to the flow divider through independent oil passages, and then connected to one port of the directional control valve through a common oil passage, and the reduction operation side pressure oil chambers of the double-acting cylinders are connected to a common oil passage. In the simultaneous telescopic boom connected to other ports of the directional control valve via oil passages, each of the oil passages connecting the extension operation side pressure oil chamber of each of the double-acting cylinders and the flow concentrator is connected to each oil passage. Branch passages connecting the oil passages to the tank are provided, and balance piston type IJ valves having a vent circuit are provided in these branch passages, and the vent circuit is controlled to open the IJ valve at any time. A device for correcting the amount of extension of a simultaneous telescopic boom, characterized in that it is equipped with an on-off valve for adjusting the amount of extension.