JPS5852045Y2 - Hydraulic feeding device of processing unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding device for a knee of a transfer machine or the like, and particularly to a hydraulic feeding device that performs the feeding using hydraulic pressure.

This type of feeding device generally shortens the machining cycle by rapidly feeding before and after a predetermined feed rate for machining.

This invention uses a differential hydraulic circuit for rapid traverse to achieve faster traverse with a small-capacity pump, and also smoothly and accurately switches between this rapid traverse and the predetermined speed for processing according to the workpiece. To provide a hydraulic feed device for a processing unit which is easy to handle and provides stable operation without using check valves that cause chattering or sequence valves that require on-site adjustment.

Below, a diagram showing an embodiment of the present invention will be described.

1 is a cylinder, and the piston rod 3 of the piston 2 is connected to a machining head 20 to which a tool 21 such as a drill or a cutting tool is attached, so as to apply feed to the machining head 20.

In addition, in the case of a processing unit that does not feed the tool 21 but feeds it to the workpiece 22 side, it is not necessary to connect the piston rod 3 to the workpiece 22 side.

P is a hydraulic power source, T is a tank, and 4 is a directional control valve for alternately connecting the hydraulic power source P and the tank T to the head side chamber 1a and the rod side chamber 1b of the cylinder 1.

Reference numeral 5 indicates a first circuit that communicates the directional switching valve 4 with the head side chamber 1a, and 6at6b indicates a second circuit that communicates the rod side chamber 1b with the directional switching valve 4 via a differential valve 9, which will be described later.

A reduction valve assembly 8 operated by a cam 7 provided on the piston rod 3 is connected to the second circuit 6a.

This deceleration valve assembly 8 includes an on-off valve 8a opened and closed by the cam 7, and a flow regulating valve 8b with pressure compensation connected in parallel to a bypass circuit 8d opened and closed by this on-off valve 8a. and a check valve 8c which is connected in parallel to these and restricts the return oil from the rod side chamber 1b and allows the opposite flow.

Reference numeral 9 denotes a differential valve whose switching is controlled by pilot pressure, and in the neutral position shown in the figure, the second rotation 6a that communicates with the rod side chamber 1b is connected to the regeneration circuit 10 that communicates with the first circuit 5. position, the second circuit 6a is connected to the directional control valve 4.
In addition, at the right switching position in the figure, the second circuit 6b on the directional control valve 4 side can be connected to the second circuit 6a on the rod side chamber 1b side. There is.

In the diagram of the differential valve 90, a first pilot circuit 11 extending from the first circuit 5 is connected to the first pilot chamber 9a on the left, and a second circuit 6b is connected to the second pilot chamber 9b on the right.
A second pilot circuit 12 extending from is connected thereto.

An on-off valve 13 operated by the cam 7 is provided in the middle of the first pilot circuit 11 .

This on-off valve 13 cuts off the supply of pilot pressure to the first pilot chamber 9a when the operating section 14 is away from the cam I, and cuts off the pilot pressure to the first pilot chamber 9a when the cam 7 is in contact with the operating section 14. It is designed to lead to the pilot room 9a.

Further, the operating section 14 is arranged slightly (several minus) before the operating section 15 of the deceleration valve assembly 8 (on the right side in the figure).

In the figure, 16 and 17 are limit switches that detect the forward and backward limits of the piston rod 3, and 1B is a dock.

Next, the operation of this device will be explained.

First, a cam 7 is installed that matches the desired range of feeding at a predetermined feed rate for machining.

Next, when the directional control valve 4 is switched to the left forward side in the figure, pressure oil is supplied from the hydraulic source P to the head side chamber 1a of the cylinder 1 through the first circuit 5, and the piston 2 is moved forward.

Pressure is generated in the first circuit 5 due to the load accompanying the forward movement of the piston 2, but since the on-off valve 13 provided in the first pilot circuit 11 is in a cutoff state, the pressure in the first circuit 5 is reduced to the differential valve 9. It is not transmitted to the first pilot chamber 9a.

On the other hand, since the second circuit 6b on the side of the directional control valve 4 is connected to the tank T, the pilot pressure transmitted to the second pilot chamber 9b of the differential valve 9 by the second pilot circuit 12 is in a low pressure state.

Therefore, the differential valve 9 is placed in the neutral position shown in the figure, and the on-off valve 8a of the reduction valve assembly 8 is placed in the open state shown in the figure because its operating portion 15 is not in contact with the cam 7. It is.

Therefore, the return oil coming out of the cylinder 10 Rondo side chamber 1b flows not only through the flow rate adjustment valve 8b of the deceleration valve assembly 8 but also through the bypass circuit 8d and towards the differential valve 9.
is returned to the first circuit 5 via the reproduction circuit 10.

This differential circuit configuration causes the piston 2 to move forward at high speed.

Thus, when the tool 21 reaches slightly before contacting the workpiece 22, the cam 7 comes into contact with the operation part 14 of the on-off valve 13, and the on-off valve 13 is opened.

The pressure in the first circuit 5 is then transmitted to the first pilot chamber 9a of the differential valve 9 via the first pilot circuit 11, and the differential valve 9 is switched to the left switching position in the figure.

By this switching, the return oil from the rod side chamber 1b is returned to the second circuit 6b and discharged to the tank T via the directional switching valve 4.

Therefore, the differential circuit configuration is released, and the piston 2 is moved forward using the normal pressure oil supply/discharge method.

A little after the on-off valve 13 is activated, the cam 7 comes into contact with the operating portion 15 of the reduction valve assembly 8, closing the on-off valve 8a.

Due to the closure of this on-off valve 8a, the return oil is transferred to the flow rate regulating valve 8b.
The piston 2 is discharged through only the piston 2 and moves the piston 2 forward at a predetermined feed rate.

Therefore, after the tool 21 is brought to a predetermined feed rate and is in a state where it can withstand a larger load, it comes into contact with the workpiece 22 and performs machining.

During this machining, the on-off valve 13 is kept open by the cam 7, and the other on-off valve 8a is kept closed by the cam 7, so the tool 21 is moved to a predetermined position determined by the flow rate regulating valve 8b. It is fed at the feed speed and completes the machining.

When the machining is completed and the piston 2 moves forward slightly, the dog 18
actuates the limit switch 16 and switches the directional control valve 4 to the reverse position on the right in the figure.

By this switching, pressure oil from the hydraulic source P is supplied to the second circuit 6b, and the first circuit 5 is opened to the tank T.

Therefore, the pressure in the first circuit 5 decreases and the pressure in the second circuit 6b increases.

Therefore, the pressure in the first pilot chamber 9a of the differential valve 9 decreases, and the pressure in the second pilot chamber 9b on the other side increases,
Switch the differential valve 9 to the right switching position in the figure.

Due to this switching, the pressure oil supplied to the second circuit 6b is
It flows into the second circuit 6a through the differential valve 9, and reaches the rod side chamber 1b through the check valve 8c of the deceleration valve assembly 8, causing the piston 2 to retreat and return to the illustrated state.

In the embodiment described above, the on-off valve 8a of the deceleration valve assembly 8
Although the example has been shown in which the on-off valve 13 of the first pilot circuit 11 is operated by one cam 7, the cams may be provided in correspondence with each other depending on the relationship between the installation positions of the two, etc. It goes without saying that various changes can be made.

As described above, according to the present invention, the interrelated configuration of the cam 7, the reduction valve assembly 8, the differential valve 9, the pilot on-off valve 13, etc. allows for rapid speed reduction using a differential circuit depending on the workpiece. Not only can feeding and machining at a predetermined feed speed be performed smoothly and accurately, it can also be easily adapted to various workpieces by changing the position of the cam or the cam. Because it does not use check valves or sequence valves, there is no chattering or on-site adjustment, and it is easy to handle and provides stable operation. Since there is no check valve or sequence valve, effects such as reducing circuit loss can be obtained.

[Brief explanation of drawings]

The figure shows an embodiment of a hydraulic feed device for a processing unit according to the present invention. DESCRIPTION OF SYMBOLS 1... Cylinder, 2... Piston, 4... Directional switching valve, 5... First circuit, 6a, 6b... Second circuit,
I...Cam, 8...Reduction valve assembly, 9...Differential valve,
10... Regeneration circuit, 11... First pilot circuit,
12...Second pilot circuit, 13...Opening/closing valve, 1
6.17...Limit switch, 18...Dock,
20... Processing head, 21... Tool, 22... Workpiece.

Claims (1)

[Claims for Utility Model Registration] A cylinder for applying feed to a tool or workpiece, and supply and discharge of pressure oil to the cylinder. a directional control valve that switches in the opposite direction; a cam attached to the member sent by the cylinder; and a cam that is operated by the cam to limit the flow rate of return oil from the rod side chamber of the cylinder to a predetermined value and to prevent the flow in the opposite direction. Check the separate reduction valve assembly to make it free, and the switching is controlled by pilot pressure, and in the neutral position the rod side chamber of the cylinder is connected to the first circuit leading from the directional control valve to the head side chamber, and in one switching position a differential valve which connects the rod side chamber to a second circuit which is paired with the first circuit and leads to the directional valve, and further connects the second circuit to the rod side chamber in the other switching position; , a first pilot circuit that guides the pressure of the first circuit to a first pilot chamber on the side where the differential valve is switched to the one switching position, and a second pilot circuit on the side where the differential valve is switched to the other switching position. operated by a second pilot circuit that guides the pressure of the second circuit into the pilot chamber, and another cam interposed in the middle of the first pilot circuit and attached to the cam or a member sent by a cylinder similarly to the cam; Hydraulic feed of a machining unit comprising an on-off valve which shuts off the first pilot circuit when the cam comes into contact with the cam, and an operating section of the on-off valve is located slightly before the operating section of the reduction valve assembly. Device