JPS6128883Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field The present invention uses a first double-acting hydraulic cylinder and a second double-acting hydraulic cylinder to drive them simultaneously to produce objects such as tables and buckets. The present invention relates to a hydraulic cylinder device for raising and lowering instruments and performing various other operations.

(b) Prior art A conventional hydraulic cylinder device having first and second double-acting hydraulic cylinders (hereinafter simply referred to as hydraulic cylinders or cylinders) uses pressure oil discharged from a hydraulic source to one side of each cylinder. Generally, the oil is introduced into a chamber to drive each of these hydraulic cylinders, and the oil discharged from the other chamber of each of these hydraulic cylinders is returned to an oil tank. However, if pressure oil is directly supplied from the hydraulic source to all the hydraulic cylinders, and the oil discharged from each hydraulic cylinder is returned to the oil tank separately, the total length of the pipe through which the oil flows will increase. There are disadvantages such as low efficiency due to the long length of the hydraulic cylinder, and the fact that the piping tends to become complicated.Also, it is difficult to establish a relationship between the operations of each hydraulic cylinder.
For example, when a particular hydraulic cylinder and another hydraulic cylinder are operated at the same speed or with a predetermined speed ratio, the hydraulic circuit becomes particularly complicated.

In order to solve this inconvenience, a circuit as shown in Figures 1 and 2 has been proposed in which the first hydraulic cylinder and the second hydraulic cylinder are operated in a certain relationship. It is being

That is, in detail, as shown in Figure 1,
The base end of an arm 2 is pivotally connected to the base 1 so as to be rotatable in upward and downward directions, and one end of a table 3 is pivotally connected to the tip of this arm 2 so as to be rotatable in upward and downward directions. . The piston rod 4a of the first hydraulic cylinder 4 pivotally connected to the base 1 is connected to the arm 2, and the piston rod 5a of the second hydraulic cylinder 5 pivotally connected to the arm 2 is suspended from one end of the table 3. It is connected to the tip of the bracket 3a. FIG. 2 shows a drive circuit for driving these hydraulic cylinders 4, 5, in which the first hydraulic cylinder 4 is connected to a hydraulic source 8 via first and second switching valves 6, 7. The second hydraulic cylinder 5 is connected to a hydraulic power source 11 via a third switching valve 9. The first switching valve 6 has ports 12, 13, 14,
15, 16, 17, 18, and the port 12 is connected to the pipe line 1.
The port 14 is communicated with the rear oil chamber 4b of the first hydraulic cylinder 4 via the port 9, and the port 14 is communicated with the front oil chamber 4c of the first hydraulic cylinder 4 via a conduit 21. Moreover, the second switching valve 7 is
It is a 4-port, 3-position manual switching valve having ports 22, 23, 24, and 25, and the port 22 is connected to the port 15 of the first switching valve 6 via a conduit 26.
, the port 23 is connected to the port 13 of the first switching valve 6 via a pipe line 27, the port 24 is connected to the hydraulic pressure source 8 via a pipe line 28, and the port 25 is connected to the oil tank. It is connected to 29.
Further, the third switching valve 9 has ports 31, 32, 3
3 and 34, the port 31 is connected to the front oil chamber 5c of the second hydraulic cylinder 5 via a pipe line 35, and the port 32 is connected to the front oil chamber 5c of the second hydraulic cylinder 5 via a pipe line 35. 36 to the rear oil chamber 5b of the second hydraulic cylinder 5, and the port 3
3 is connected to the hydraulic power source 11 via a conduit 37, and the port 34 is communicated with an oil tank 38. Also, from the middle of the pipes 35, 36, the pipes 41, 4
2 are branched, and these pipes 41 and 42 are connected to each other.
are connected to ports 16 and 17 of the first switching valve 6, respectively.

Next, the operation of this conventional example is described below () ~
The case of () will be explained separately.

() When the first switching valve 6 and the second switching valve 7 are linked and switched to the same position.

In this case, ports 12 and 16, ports 14 and 15, and ports 17 and 18 of the first switching valve 6 are in communication with each other. Further, the ports 22 and 24, and the ports 23 and 25 of the second switching valve 7 are in communication with each other. Therefore, the pressure oil discharged from the hydraulic source 8 passes through the main shaft pressure circuit constituted by the pipes 28, 26.21 to the first hydraulic cylinder 4.
The oil is supplied to the front oil chamber 4c of the arm 2, and the piston rod 4a retracts to the right in the figure.
rotates downward. Further, the pressure oil discharged from the rear oil chamber 4b of the first hydraulic cylinder 4 passes through the auxiliary hydraulic circuit constituted by the pipes 19, 41, and 35 to the front oil chamber 5c of the second hydraulic cylinder 5.
The piston rod 5a is supplied to the piston rod 5a.
moves toward the right in the figure, and the table 3 rotates upward relative to the arm 2. Therefore, the absolute value of the angular velocity of arm 2 with respect to base 1 and arm 2
If the mounting positions of the hydraulic cylinders 4 and 5 are adjusted so that the absolute value of the angular velocity of the table 3 is equal to the absolute value of the angular velocity of the table 3 relative to the become.

() When the first switching valve 6 and the second switching valve 7 are linked and switched to the same position.

In this case, ports 12 and 13, ports 14 and 17, and ports 16 and 18 of the first switching valve 6 are in communication with each other. Furthermore, the ports 22 and 25, and the ports 23 and 24 of the second switching valve 7 are brought into communication, respectively. Therefore, the pressure oil discharged from the hydraulic source 8 passes through the main hydraulic circuit constituted by the pipes 28, 27, and 19 to the first hydraulic cylinder 4.
When the oil is supplied to the rear oil chamber 4b, the piston rod 4a projects to the left in the figure and the arm 2 rotates upward. Moreover, the pressure oil discharged from the front oil chamber 4c of this first hydraulic cylinder 4 is
2 and 36 to the rear oil chamber 5b of the second hydraulic cylinder 5, the piston rod 5a protrudes to the left in the figure, and the table 3 rotates downward with respect to the arm 2. . Therefore, contrary to the case () above, the table 3 rises while maintaining a predetermined posture.

() When the second switching valve 7 is switched alone.

When only the second switching valve 7 is switched to the above position, pressure oil discharged from the hydraulic source 8 is supplied to the oil chamber 4c or 4b of the first hydraulic cylinder 4, and the hydraulic cylinder 4 operates independently. Then, the pressure oil discharged from the hydraulic cylinder 4 returns to the switching valve 7 through the pipe 27 or 26 and is returned to the oil tank 29 from the port 25.

() When the third switching valve 9 is switched alone.

When only the third switching valve 9 is switched to the position or , the pressure oil discharged from the hydraulic source 11 is supplied to the oil chamber 5c or 5b of the second hydraulic cylinder 5, and the pressure oil discharged from the hydraulic cylinder 5 is transferred to the pipe. The oil is returned to the switching valve 9 via the channel 36 or 35 and from the return port 34 to the oil tank 38.

The conventional device, that is, the one shown in FIG. 2, operates as described above, but if the first hydraulic cylinder 4 and the second hydraulic cylinder 5 are simply connected in series, The entire amount of return oil discharged from the first cylinder 4 is supplied to the second cylinder 5. Therefore, when the capacities of the two cylinders 4 and 5 are greatly different, or when the position of the point of action of the hydraulic cylinders 4 and 5 with respect to the arm 2 or the bracket 3a is restricted for some reason, the table 3 This leads to a situation in which it becomes impossible to make the robot move as desired, for example, to move while always maintaining a horizontal position.

(C) Purpose The present invention was made with attention to the above-mentioned circumstances, and it is an object of the present invention to operate a first double-acting hydraulic cylinder and a second double-acting hydraulic cylinder with a desired speed relationship. It is an object of the present invention to provide a hydraulic cylinder device that can increase the degree of freedom in design when incorporating these cylinders into various types of equipment, including the above-mentioned lifting device.

(d) Configuration In order to achieve the above object, the present invention includes a hydraulic circuit that guides a portion of the return oil discharged from the other chamber of the first hydraulic cylinder to the second hydraulic cylinder. Features.

(E) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 (FIG. 3) The circuit of this embodiment is an improvement of the circuit shown in FIG. 2, and the same or corresponding parts are given the same symbols and their explanation will be omitted.

This thing has check valves 44 and 4 in the pipes 41 and 42.
Flow rate control valves 46 and 47 with 5 are interposed.
The flow control valves 46 and 47 are for controlling the amount of return oil supplied from the first hydraulic cylinder 4 to the second hydraulic cylinder 5.
A part of the return oil, that is, the discharged pressure oil, is divided and one of them is supplied (divided) to the second hydraulic cylinder 5, and the remaining pressure oil of the other divided part is sent to the pipe 48, It is designed to be returned to the tank through 49.

Next, the operation of this embodiment is described below (') to
The case (') will be explained separately.

(') When the first switching valve 6 and the second switching valve 7 are linked and switched to both positions.

Basically, it is the same as the above-mentioned (), and the pressure oil discharged from the hydraulic source 8 is
The oil is supplied to the front oil chamber 4c of the first hydraulic cylinder 4 through the main hydraulic circuit constituted by 6 and 21, and the piston rod 4A retracts to the right in the figure. Moreover, the pressure oil discharged from the rear oil chamber 4b of this first hydraulic cylinder 4 is
The oil is supplied to the front oil chamber 5c of the second hydraulic cylinder 5 through an auxiliary hydraulic circuit constituted by 9, 41, and 35. The difference from the above () is that a flow control valve 46 with a check valve 44 is interposed in the conduit 41 of the auxiliary hydraulic circuit, so that the return oil flowing through the auxiliary hydraulic circuit is controlled. Only a portion is supplied to the second hydraulic cylinder 5, and the rest is returned to the tank one after another.

(') When the first switching valve 6 and the second switching valve 7 are linked and switched to both positions.

This case is also basically the same as the above (). That is, the pressure oil discharged from the hydraulic source 8 is supplied to the rear oil chamber 4b of the first hydraulic cylinder 4 through the main hydraulic circuit constituted by the pipes 28, 27, and 19, and the piston rod 4a is It protrudes to the left in the figure. Further, the pressure oil discharged from the front oil chamber 4c of the first hydraulic cylinder 4 passes through the auxiliary hydraulic circuit constituted by the pipes 21, 42, and 36 to the rear oil chamber 5b of the second hydraulic cylinder 5. Supplied. The difference from the above () is that a flow control valve 47 with a check valve 45 is interposed in the conduit 42 of the auxiliary hydraulic circuit, so that the return oil flowing through the auxiliary hydraulic circuit is controlled. Only a portion is supplied to the second hydraulic cylinder 5, and the rest is returned to the tank one after another.

(') When the second switching valve 7 is switched alone.

It operates in the same way as () above.

(') When the third switching valve 9 is switched alone.

It operates in the same way as () above.

The above-mentioned operation is obtained, but according to this embodiment, when the two hydraulic cylinders 4 and 5 are operated simultaneously, the return oil discharged from the first hydraulic cylinder 4 is transferred to the second hydraulic cylinder. 5 to drive the hydraulic cylinder 5,
The amount of return oil discharged from the first hydraulic cylinder 4 is directly related to the operating amount of the hydraulic cylinder 4, and if a part of this return oil is used to drive the second hydraulic cylinder 5. , the first hydraulic cylinder 4 and the second hydraulic cylinder 5 at the same speed,
Alternatively, it can be operated with a predetermined speed ratio. That is, if it is like this,
For example, even if the bore diameter of the second hydraulic cylinder 5 is extremely smaller than the bore diameter of the first hydraulic cylinder 4, by keeping the set flow rates of the flow rate control valves 46 and 47 low, both the hydraulic cylinders can be 4,
5 can be operated at the same or similar speed. Alternatively, even if the bore diameters of both the hydraulic cylinders 4 and 5 are the same, the two hydraulic cylinders 4 and 5 can be operated at completely different speeds while maintaining a constant speed ratio. Therefore, with such a structure, when the cylinders 4 and 5 are used in the manner shown in FIG. 1, the degree of freedom in design etc. is extremely wide. In other words, the bore diameter of the cylinders 4, 5, the length of the arm 2 or the bracket 3a, etc. are determined by factors that are completely unrelated to the operating speed, such as the load acting on each cylinder 4, 5, space requirements, etc. Even in the case where the optimum value is determined based on It is also easy to set it so that it moves while maintaining the same.

In this way, the operation of rotating the arm 2 while keeping the posture of the table 3 constant,
This can be realized with a simple configuration without introducing a complicated hydraulic circuit.

Embodiment 2 (FIG. 4) In the first embodiment, a case was explained in which three switching valves were used to control two hydraulic cylinders, but as shown in FIG. Almost the same effect can also be obtained. That is, what is shown in FIG. 4 is the first hydraulic cylinder 4.
is connected to a hydraulic power source 52 via a first switching valve 51, and the second hydraulic cylinder 5 is connected to a second switching valve 53.
It is connected to a hydraulic power source 52 via. The first switching valve 51 has ports 54, 55, 56, 57, 58,
59, 60, 61, the port 56 is connected to the front oil chamber 4c of the first hydraulic cylinder 4 via a pipe 62, and the port 57 is connected to the front oil chamber 4c of the first hydraulic cylinder 4 via a pipe 62. It is connected to the rear oil chamber 4b of the first hydraulic cylinder 4 via a line 63, and the port 60 is connected to the hydraulic power source 52 via a line 64 and a line 65. Further, the second switching valve 53 has six ports 66, 67, 68, 69, 70, and 71.
This is a three-port manual switching valve, in which the port 66 is connected to the front oil chamber 5c of the second hydraulic cylinder 5 via a pipe 72, and the port 67 is connected to a pipe 73.
The port 70 is connected to the rear oil chamber 5b of the second hydraulic cylinder 5 via the port 70, and the hydraulic source 5
Connected to 2. Further, pipes 74 and 75 are branched from the middle of the pipes 72 and 73, and the tips of these pipes 74 and 75 are connected to the first switching valve 51.
are connected to ports 54 and 55, respectively. Flow control valves 86 and 87 with check valves 84 and 85 are provided in the pipes 74 and 75, respectively. The flow control valves 86 and 87 are for controlling the amount of pressure oil supplied from the first hydraulic cylinder 4 to the second hydraulic cylinder 5, and only a portion of the return oil discharged from the first hydraulic cylinder 4 is provided. is supplied to the second hydraulic cylinder 5. The excess pressure oil is then returned to the tank through pipes 88 and 89.

Next, the operation of this second embodiment will be explained separately for the following cases (a) to (d).

(a) When the first switching valve 51 is switched to the position.

In this case, ports 54 and 59, ports 55 and 56, ports 57 and 6
0 are in communication with each other. Therefore, the pressure oil discharged from the hydraulic source 52 is transferred to the pipes 65 and 6.
4 and 63 to the rear oil chamber 4b of the first hydraulic cylinder 4, and the piston rod 4a protrudes to the left in the figure. Then, the pressure oil discharged from the front oil chamber 4c of this hydraulic cylinder 4 is transferred to the pipes 62 and 7.
5 and 73 to the rear oil chamber 5b of the second hydraulic cylinder 5, causing the piston rod 5a of the hydraulic cylinder 5 to protrude to the left in the figure. In addition, since a flow control valve 87 with a check valve 85 is interposed in the pipe line 75 of the auxiliary hydraulic circuit, only a portion of the return oil flowing through the auxiliary hydraulic circuit is directed to the second hydraulic cylinder 5. supply and the rest is returned to the tank.

(b) When the first switching valve 51 is switched to the position.

In this case, the port 54 of the first switching valve 51
and port 57, port 55 and port 59, and port 56 and port 60, respectively, are brought into communication. Therefore, the pressure oil discharged from the hydraulic source 52 is supplied to the front oil chamber 4c of the first hydraulic cylinder 4 through the main hydraulic circuit constituted by the pipes 65, 64, and 62, and the piston rod 4a is Immerse yourself in the right side of the diagram. Pressure oil discharged from the rear oil chamber 4b of the hydraulic cylinder 4 is supplied to the front oil chamber 5c of the second hydraulic cylinder 5 through the auxiliary hydraulic circuit constituted by pipes 63, 74, and 72. As a result, the piston rod 5a retracts to the right in the figure. However, since a flow control valve 86 with a check valve 84 is interposed in the conduit 74 of the auxiliary hydraulic circuit, only a part of the return oil flowing through the auxiliary hydraulic circuit flows into the second hydraulic cylinder 5. supply and the rest is returned to the tank.

(c) When the second switching valve 53 is switched to the position.

In this case, the port 66 of the second switching valve 53
and port 69, and port 67 and port 70 are brought into communication, respectively. Therefore, the hydraulic source 52
Pressure oil discharged from the piston rod 5a is supplied to the rear oil chamber 5b of the second hydraulic cylinder 5 through the pipes 65 and 73, and the piston rod 5a protrudes to the left in the figure. In this case, the return oil discharged from the front oil chamber 5c of this hydraulic cylinder 5 is transferred to the pipe 72.
The oil returns to the second switching valve 53 through the port 69 and is returned to the oil tank 76. Therefore, the second hydraulic cylinder 5 operates independently.

(d) When the position of the second switching valve 53 is changed.

In this case, the port 66 of the second switching valve 53
and port 70, and port 68 and port 69 are brought into communication. Therefore, the hydraulic source 52
Pressure oil discharged from the piston is supplied to the front oil chamber 5c of the second hydraulic cylinder 5 through the pipes 65 and 72, and the piston rod 5a retracts to the right in the figure. In this case, the return oil discharged from the rear oil chamber 5b of this hydraulic cylinder 5 is passed through the pipe 73.
The oil returns to the second switching valve 53 through the port 69, and is returned to the oil tank 76 through the port 69. Therefore, the second hydraulic cylinder 5 operates independently.

In this embodiment, when the first and second hydraulic cylinders 4 and 5 are operated simultaneously,
A part of the return oil discharged from the first hydraulic cylinder 4 is guided to the second hydraulic cylinder 5.
Since the valves 51 and 53 are driven by the actuator 51a, 51b, and 51c, effects similar to those of the first embodiment can be obtained. Moreover, in the case of the second embodiment, it is possible to use the so-called mono-spool valve type for the switching valves 51 and 53 so that the above-mentioned switching operations (a) to (d) can be performed by a single operating lever.

Although each of the above-mentioned embodiments describes the case where the present invention is applied to the attitude control of the table 3, the present invention is of course not limited to this. For example, as shown in FIG. As shown in Fig. 6, the present invention can be applied to a variety of applications, including the case where the attitude of a bucket 92 pivotally attached to the tip of a rotating arm 91 of a shovel, bucket hoe, or loader is controlled by hydraulic cylinders 4 and 5. . In other words, it can be applied to various devices using the first double-acting hydraulic cylinder and the second double-acting hydraulic cylinder of the present invention, and its use is not limited to posture control of tables, buckets, etc. Furthermore, the number of hydraulic cylinders is not limited to two. When applied to a device using three or more hydraulic cylinders, a portion of the return oil discharged from a single first hydraulic cylinder may be used to drive a plurality of second hydraulic cylinders, or a plurality of first hydraulic cylinders may be driven. Driving a plurality of second hydraulic cylinders with a portion of return oil discharged from a plurality of hydraulic cylinders, driving a single second hydraulic cylinder with a portion of return oil discharged from a plurality of first hydraulic cylinders, etc. Other aspects are also possible.

(f) Effects As detailed above, according to the present invention, the first double-acting hydraulic cylinder and the second double-acting hydraulic cylinder can be operated with a desired speed relationship, It is possible to provide a hydraulic cylinder device that can increase the degree of freedom in design when incorporating these cylinders into various types of equipment.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a conventional example, and FIG. 2 is a circuit explanatory diagram showing the conventional example. FIG. 3 is a circuit explanatory diagram showing one embodiment of the present invention, FIG. 4 is a circuit explanatory diagram showing another embodiment of the present invention, and FIGS. 5 and 6 are different embodiments of the present invention. FIG. 4...First double-acting hydraulic cylinder, 4b...Chamber (rear oil chamber), 4c...Chamber (front oil chamber), 5...Second double-acting hydraulic cylinder, 8, 11, 52... Hydraulic source.

Claims (1)

[Scope of utility model registration request] A main hydraulic circuit that leads pressure oil to one chamber of the first and second double-acting hydraulic cylinders, a first double-acting hydraulic cylinder, and a second double-acting hydraulic cylinder. A hydraulic cylinder device comprising: an auxiliary hydraulic circuit that guides a portion of the oil returned from the chamber.