JP2024134797A - Hydraulic pump unit feed rate change valve device - Google Patents

Abstract

[Problem] To provide a feed speed switching valve device for configuring a pump unit capable of switching between control for high-speed and low-speed piston feed and control for low-speed piston feed only. [Solution] The feed speed switching valve device 9 comprises a valve case 91, a poppet valve body 92, a valve rod 93, and a crank lever 94. The crank lever 94 rotates 180 degrees forward and backward to place the valve rod 93 in the high-speed feed position or the low-speed feed position. When the valve rod 93 is in the high-speed feed position, the poppet valve body 92 closes the inlet 91a by the relief spring 95, and oil from the two pumps 3a, 3b is sent to the oil passage 7 until the set oil pressure of the spring 95 is reached, and the piston is fed at high speed. When the valve rod 93 is in the low-speed feed position, the poppet valve body 92 is pulled up to the open position, oil is discharged from the pump 3b, and the piston is fed at low speed only by the pump 3b. [Selected Figure] Figure 3

Description

Application for exception to loss of novelty has been filed

The present invention relates to a manual switching valve device that is provided to switch the piston feed speed in a pump unit connected to a cylinder of a hydraulic tool such as a compressor for a sleeve for connecting electric wires.

Conventionally, there is known a pump unit equipped with two types of pumps, one for low pressure and one for high pressure, an engine to drive the pumps, and a control device to control the oil supply from the pumps. In this pump unit, the oil discharged from the pump is made to flow into a cylinder through an oil passage, and the piston is first advanced at high speed. When the die comes into contact with the material to be compressed and a predetermined pressure is reached, the valve is switched to perform the main compression at low speed and high pressure using the high pressure pump (for example, Patent Document 1).

Japanese Patent Application Publication No. 58-57503

The above-mentioned conventional pump unit cannot be applied to a hydraulic tool in which only slow feed is required without the fast feed step.
Therefore, an object of the present invention is to provide a feed speed switching valve device for constructing a pump unit that can be applied to various hydraulic tools by switching between control that sequentially performs fast and slow feed of the piston, and control that performs only slow feed.

In the following description, reference will be made to the figures of the accompanying drawings, in which: FIG.
In order to solve the above problems, the feed speed switching valve device 9 of the present invention is interposed between one pump 3b and an oil passage 7 in a pump unit 4 in which two types of pumps 3a, 3b are connected in series to an oil passage 7. The feed speed switching valve device 9 includes a valve case 91, a poppet valve body 92, a valve rod 93, and a crank lever 94. The valve case 91 has an inlet 91a communicating with one pump 3b and the oil passage 7, and an oil drain port 91b communicating with the inlet 91a and an oil tank 10. The poppet valve body 92 is assembled in the valve case 91 so as to be movable in the axial direction to two positions: a closed position in which the inlet 91a is closed to send oil from one pump 3b to the oil passage 7, and an open position in which the inlet 91a is opened to drain oil from one pump 3b, and is biased to the closed position by a relief spring 95. The valve rod 93 has one end connected to the poppet valve element 92 inside the valve case 91, and the other end protruding from the valve case 91 to the outside, and is assembled so as to be movable in the axial direction to two positions: a high-speed feed position retracted into the valve case 91, and a low-speed feed position pulled out. A crank lever 94 is connected to the other end of the valve rod 93 outside the valve case 91, and switches the valve rod 93 to two positions: the high-speed feed position and the low-speed feed position. The valve rod 93 is biased to the high-speed feed position by a compression spring 96 having a larger spring constant than the relief spring 95, and the valve rod 93 and the poppet valve element 92 are connected with a predetermined play in the axial direction so that when the valve rod 93 is in the high-speed feed position, the poppet valve element 92 is free from the valve rod 93 and is disposed in the closed position, and when the valve rod 93 is in the low-speed feed position, the poppet valve element 92 is pulled up to the open position by the valve rod 93. When the valve rod 93 is in the high-speed feed position, the two pumps 3a, 3b rapidly feed the piston up to the set pressure of the relief spring 95, and when the valve rod 93 is in the low-speed feed position, rapid forwarding of the piston is not performed.

The feed speed switching valve device of the present invention can be used to configure a pump unit that can be used with various hydraulic tools by switching between control that sequentially performs fast and slow piston feed, and control that performs only slow feed.

1 is an explanatory diagram of a pump unit equipped with a feed rate switching valve device of the present invention; FIG. 2 is a hydraulic circuit diagram of a pump unit equipped with the feed rate switching valve device of FIG. FIG. 2 is a cross-sectional view of the feed rate switching valve device of the present invention.

An embodiment of the present invention will be described with reference to the drawings.
1, a hydraulic pump unit 1 includes a drive device 2 such as a motor or an engine, a hydraulic pump 3 driven thereby, and a control device 4 for controlling oil fed from the pump 3. A cylinder 6 of a compressor 5 is connected to the control device 4 via two oil passages, a pressurized oil passage 7a and a return oil passage 7b. The control device 4 includes a manual change-over valve 8 and a feed speed change-over valve device 9.

Figure 2 shows the hydraulic circuit of the control device 4. The pump 3 consists of two pumps: a pump 3a for high pressure and low speed, and a pump 3b for low pressure and high speed. In Figure 2, the pump 3 is running, but the switching valve 8 is in the neutral position, and no oil is being sent to the cylinder 6.

Now, when the feed speed change valve device 9 is switched to the high speed feed position on the left side of the figure and the manual change valve 8 is switched to the on position, the oil from both pumps 3a and 3b joins the oil passage 7 and flows into the oil passages 7a and 7b through the manual change valve 8. The cylinder 6 fast forwards the piston 10, and when the movable die 11 of the compressor 5 abuts against the compressed body (not shown), the oil pressure in the oil passage 7 rises, and when it reaches about 50 kg/ ^cm2 , for example, the feed speed change valve device 9 is unloaded, and thereafter compression and feed are performed only by the pump 3a.

Also, when the feed speed switching valve device 9 is switched to the low-speed feed position on the right side of the figure and the manual switching valve 8 is switched to the on position, oil from the low-pressure, high-speed pump 3b is unloaded from the beginning, and only the oil from pump 3a flows through the manual switching valve 8 into the oil passages 7a and 7b, and the compressor 5 operates slowly.

The structure of the feed speed switching valve device 9 is shown in Figure 3. The feed speed switching valve device 9 comprises a valve case 91, a poppet valve body 92 assembled thereto, a valve stem 93, and a crank lever 94.

The valve case 91 has an inlet 91a and an oil drain port 91b that communicates with the inlet 91a. The inlet 91a communicates with the low pressure, high speed pump 3b and the oil passage 7. The oil drain port 91b communicates with the inlet 91a and the oil tank 10.

The poppet valve body 92 is assembled in the valve case 93 so as to be movable in the axial direction, and in the closed position shown in FIG. 3(A), the tip closes the inlet 91a, and in the open position shown in FIG. 3(B), the tip opens the inlet 91a and is biased to the closed position by the relief spring 95. Therefore, when the poppet valve body 92 is in the closed position, oil from the pump 3b is sent to the oil passage 7, and when the poppet valve body 92 is in the open position, oil from the pump 3b is drained from the oil drain port 91b. The poppet valve body 92 is provided with a connection hole 92a of a predetermined depth along the axis on the base end side that receives the tip of the valve rod 93 so as to be relatively movable in the axial direction.

The valve rod 93 is assembled in the valve case 91 so as to be movable in the axial direction, and one end side is received in the connection hole 92a of the poppet valve body 92 in the valve case 91 so as to be movable relatively in the axial direction, and is connected to the poppet valve body 92 via the long hole 93a and the pivot pin 92b. The other end side of the valve rod 93 protrudes to the outside from the valve case 91, and is connected to the crank lever 94 via the long hole 93b and the pivot pin 94a. The valve rod 93 is constantly pulled inward of the valve case 91 by a compression spring 96 with a spring constant larger than that of the relief spring 95.

The crank lever 94 has a base end with a circumferential surface 94b, which is pivoted by a pivot pin 94a to the long hole 93b of the valve rod 93 on the outside of the valve case 91. The pivot pin 94a is located eccentrically with respect to the circumferential surface 94b, and pivots the valve rod 93 with the compression spring 96 constantly compressed. Therefore, the pivot pin 94a is always located at the outer end of the long hole 93a, and the circumferential surface 94a of the crank lever 94 is always pressed against the outer end surface of the valve case 91. Therefore, the crank lever 94 rotates forward and backward by 180 degrees while sliding the circumferential surface 94a against the outer end surface of the valve case 91, thereby switching the valve rod 93 between two positions, a high-speed feed position (Figure 3 (A)) and a low-speed feed position (Figure 3 (B)).

The valve body 92 and the valve rod 93 are connected with a certain amount of play in the axial direction by the engagement of the pivot pin 92b and the long hole 93a. When the valve rod 93 is in the high-speed feed position, the pivot pin 92 is in the middle position of the long hole 93a, and the poppet valve body 92 is free from the valve rod 93 and is positioned in the closed position by the relief spring 95. When the valve rod 93 is in the low-speed feed position, the pivot pin 92b abuts against the tip of the long hole 93a, and the poppet valve body 92 is pulled up to the open position by the valve rod 93.

Therefore, when the valve rod 93 is in the high-speed feed position (Fig. 3(A)), the inlet 91a is closed and oil from the two pumps 3a and 3b is sent to the oil passage 7 until the oil pressure in the oil passage 7 reaches the set pressure of the relief spring 95, and the piston is fast-forwarded. When the oil pressure in the oil passage 7 exceeds the set pressure of the relief spring 95, the inlet 91a opens and oil from the pump 3b is drained from the oil drain port 91b, fast-forwarding ends, and slow-speed feeding by only the pump 3a continues. On the other hand, if the valve rod 93 is in the low-speed feed position (Fig. 3(B)), the inlet 91a is open from the beginning and oil from the pump 3b is drained, so the piston is not fast-forwarded and only slow-speed feeding is performed.

1 Hydraulic pump unit 2 Engine (drive unit)
Reference Signs List 3 Pump 3a Pump 3b Pump 4 Hydraulic control device 5 Compressor 6 Hydraulic cylinder 7 Oil passage 7a, 7b Oil passage 8 Manual changeover valve 9 Feed speed changeover valve device 91 Valve case 91a Inlet 91b Oil drain port 92 Petpot valve body 92a Connection hole 92b Pivot pin 93 Valve stem 93a Slotted hole 93b Slotted hole 94 Crank lever 94a Pivot pin 94b Circumferential surface 95 Relief spring 96 Compression spring 10 Piston 11 Movable die

Claims (2)

A pump unit comprising two types of pumps, a drive device for driving the pumps, and a control device for controlling oil sent from the pumps to a cylinder through an oil passage, the two types of pumps being connected in series to the oil passage within the control device,
A piston feed speed switching valve device interposed between one of the two types of pumps and the oil passage,
a valve case having an inlet communicating with one of the pumps and the oil passage, and an oil drain port communicating with the inlet and an oil tank;
a poppet valve body mounted in the valve case so as to be movable in an axial direction to two positions, a closed position for closing the inlet to send oil from the one pump to the oil passage and an open position for opening the inlet to discharge oil from the one pump, and biased to the closed position by a relief spring;
a valve rod having one end connected to the poppet valve body within the valve case and the other end protruding from the valve case to the outside, the valve rod being assembled so as to be movable in the axial direction to two positions: a high-speed feed position where the valve rod is pushed into the valve case, and a low-speed feed position where the valve rod is pulled out;
a crank lever connected to the other end of the valve rod outside the valve case for switching the valve rod to two positions, a high-speed feed position and a low-speed feed position;
The valve stem is biased to a high-speed feed position by a compression spring having a spring constant greater than that of the relief spring;
The valve stem and the poppet valve element are connected with a predetermined amount of play in the axial direction so that when the valve stem is in a high-speed feed position, the poppet valve element is free from the valve stem and disposed in a closed position, and when the valve stem is in a low-speed feed position, the poppet valve element is pulled up to an open position by the valve stem;
A feed speed switching valve device characterized in that when the valve rod is in a high-speed feed position, the two pumps fast-forward the piston up to the set pressure of the relief spring, and when the valve rod is in a low-speed feed position, the fast-forwarding of the piston is terminated. The poppet valve body has a connection hole of a predetermined depth extending from the end of the valve stem side along the axis,
2. The feed speed switching valve device according to claim 1, wherein one end of the valve rod, which has an axial long hole, is inserted into the connecting hole of the poppet valve body, and a pin passing through the long hole allows the valve rod to move axially relative to the poppet valve body within the range of the long hole, and the pin is positioned at an intermediate position of the long hole at a fast-forward position, so that the poppet is positioned at a closed position only by the biasing force of the relief spring.

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