JPS6144750Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feed control device that is used to control the feed of a machine tool or the like and operates a liquid cylinder intermittently. In general, this type of feed control device includes an electromagnetically operated on-off valve disposed in a flow path connecting a pressure source and an operating flow path on the discharge side of a liquid cylinder, as shown in Japanese Utility Model Publication No. 56-25789. By repeatedly operating the movable body, the movable body is intermittently stopped or moved backward, so that fine chips can be obtained by cutting with a cutting tool provided on the movable body.

However, there are drawbacks such as the need for an electrical circuit separate from the hydraulic circuit to operate the electromagnetically operated on-off valve, which complicates the configuration of the control device and makes it difficult to install into existing equipment. It was hot.

The present invention eliminates such drawbacks and provides a feed control device that eliminates the need for an electric circuit for controlling the intermittent feed of a liquid cylinder, provides reliable intermittent feed control, and is easy to install in existing equipment. It is something.

For this reason, the present invention installs a flow rate control valve in the working flow path on the discharge side of the liquid cylinder when feeding and controlling the moving body, and also installs a rotation direction switching valve connected to the working flow path on the supply side. The rotation direction switching valve has an internal gear rotatably inserted into a fitting hole in the housing, and an external gear is eccentrically engaged with the internal gear to control the pressure liquid in the supply side working flow path. The internal gear and external gear are provided to rotate due to supply, and the inner surface of the fitting hole into which the internal gear fits is equipped with a pilot load port, a pilot supply port connected to the supply side, and a pilot discharge port connected to the low pressure side. In addition, a switching groove is formed on the outer surface of the internal gear so that the pilot load port can be switched between the pilot supply port and the pilot discharge port by the rotation of the internal gear, and a piston is slid inside. A large-diameter working chamber and a small-diameter pressure intensifying chamber are formed by movably fitting the valve, and the working chamber is communicated with the pilot load port of the rotary switching valve, thereby switching communication between the pilot supply port and the pilot discharge port of the pilot load port. A liquid pressure intensifier is provided so that the piston reciprocates and discharges the pressurized liquid from the pressure intensifier chamber every time the piston reciprocates and discharges the pressurized liquid from the pressure intensifier chamber. The liquid cylinder is connected upstream of the flow rate control valve of the passageway to operate the liquid cylinder intermittently.

In this configuration of the present invention, when pressure liquid is supplied to the working flow path on the supply side of the liquid cylinder,
The external gear and internal gear of the rotation direction switching valve rotate, and as the internal gear rotates, a switching groove formed on the outer surface of the internal gear switches the pilot load port to the pilot supply port and pilot discharge port, increasing the fluid flow. The piston of the pressure device reciprocates every time the pilot supply port and pilot discharge port of the pilot load port are switched, and the pressure-increasing liquid in the pressure-increasing chamber is intermittently connected to the flow rate control valve upstream of the working flow path which becomes the discharge side of the liquid cylinder. The liquid cylinder operates intermittently, stopping or retracting each time the pressure-increasing liquid is supplied to the discharge-side working flow path. Therefore, an electric circuit for controlling the intermittent feeding of the liquid cylinder can be made unnecessary, and reliable intermittent feeding control can be obtained.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 3, reference numeral 1 denotes a liquid cylinder, into which a piston 2 is slidably fitted to form divided working chambers 3 and 4, and a piston rod 5 that protrudes outside has a workpiece at its tip. A moving body 7 equipped with a cutting tool 6 (not shown) is connected thereto. Reference numeral 8 denotes a main switching valve that switches and controls the flow direction of the liquid, and is connected to each of the working chambers 3 and 4 of the liquid cylinder 1 via working channels 9 and 10. The operating flow path 9 includes an on-off valve 11 that is mechanically operated by a dog (not shown) provided on the movable body 7 and a flow control valve 1 with pressure compensation.
2 and a check valve 14 that only allows liquid flow to the working chamber 4 are arranged in parallel. 15 is a rotation direction switching valve, which has a front cover 17 and a rear cover 1 on both sides of the main body 16.
The internal gear 20 is rotatably fitted into the fitting hole 19 in the casing formed by integrally fastening the external gear 21 with the internal gear 20 using a plurality of bolts 13, and the external gear 21 is eccentrically engaged with the internal gear 20. The air space formed between the internal gear 20 and the external gear 21 is divided into a high-pressure chamber 23 and a low-pressure chamber 24 by a separating plate 22. Pressure liquid is supplied from the port 25 to the high pressure chamber 23, and the low pressure chamber 24 and the rear lid 1 are
The internal gear 20 and the external gear 21 are provided so that the internal gear 20 and the external gear 21 are rotated by discharging the liquid to a low-pressure side liquid tank 27 through a discharge port 26 provided at 8. The rotational direction switching valve 15 has a pilot load port 30 and a pilot supply port 31 opened on the same circumference and spaced apart in the axial direction on the inner surface of the fitting hole 19, and a pilot discharge port 32 and the pilot load port 30 are opened on the same axis. The switching groove 28 is opened at intervals in the circumferential direction and extends in the circumferential direction so as to communicate with the pilot load port 30 and the pilot discharge port 32 on the outer surface of the internal gear 20. A switching groove 29 is recessed and extends in the axial direction so as to communicate with the pilot supply port 31;
By rotating the internal gear 20, the pilot load port can be repeatedly switched to communicate with the pilot discharge port 32 and the pilot supply port 31. The pilot outlet 32 is connected to the liquid tank 27. Reference numeral 33 denotes a flow path that branches from the operating flow path 10 and connects to the supply port 25 of the rotational direction switching valve 15;
A flow control valve 34 is installed to adjust the rotation speed of the engine. Reference numeral 35 denotes a pilot flow path that branches from the flow path 33 upstream of the flow rate control valve 34 and connects to the pilot supply port 31 of the rotational direction switching valve 15. 36
is a liquid pressure intensifier, in which a piston 37 is slidably fitted to form a large diameter working chamber 38 and a small diameter pressure intensifying chamber 39.
The working chamber 38 is connected to the pilot load port 30 of the rotational direction switching valve 15 through a flow path 40, and the pressure boosting chamber 39 is connected to the pilot flow path 35 through a flow path 41. 42, it is connected upstream of the on-off valve 11, flow rate control valve 12, etc. of the operating flow path 9. 43 is an adjustment screw for adjusting the sliding amount of the piston 37 of the liquid pressure intensifier 36, 45 and 46 are check valves installed in the flow paths 41 and 42 so that the pressure intensification chamber 39 of the liquid pressure intensifier 36 acts as a pump, and 47 is a A flow control valve 48 is a pressure source, which is installed in the flow path 42 and controls the amount of pressurized liquid supplied to the working chamber 4 of the liquid cylinder 1.

Next, the operation of this configuration will be explained.

In FIG. 1, the main switching valve 8 is in the central switching position, communicating both the two working channels 9 and 10 with the liquid tank 27, and the liquid cylinder 1 is stopped.

When the main switching valve 8 is operated to the left switching position, the working flow path 9 is connected to the liquid tank 27, and the working flow path 10 is connected to the pressure source 48.
The liquid cylinder 1 is operated by the pressure liquid supplied to the working chamber 3 and moves the movable body 7 forward. At the initial stage of operation of the liquid cylinder 1, the liquid in the working chamber 4 flows through the on-off valve 11 and the working flow path 9 to the liquid tank 27.
Since the movable body 7 is ejected, the movable body 7 is sent forward. At this time, the pressure liquid in the operating flow path 10 is supplied to the supply port 25 of the rotation direction switching valve 15 through the flow path 33, causing the internal gear 20 and the external gear 21 to rotate clockwise. The pilot load port 30 is connected to the pilot supply port 31 via the switching groove 29 due to the rotation of
Pressurized liquid is supplied to the working chamber 38 of a liquid pressure intensifier 36 which is connected to the pilot load port 30 via the flow path 40 by communicating with the pilot discharge port 32 through the switching groove 28. The liquid is discharged to the liquid tank 27. The liquid pressure intensifier 36 causes the piston 37 to move into the working chamber 3 by supplying pressure liquid to the working chamber 38 or discharging the liquid from the working chamber 38 to the liquid tank 27.
It slides back and forth due to the pressure difference between 8 and the pressure intensifying chamber 39,
The pressure increasing liquid discharged from the pressure increasing chamber 39 as the piston 37 slides back and forth flows through the flow path 42 and the flow rate control valve 47.
The liquid is intermittently supplied to the working channel 9 through the on-off valve 11, flows through the working channel 9, and is discharged to the liquid tank 27, and the movable body 7 is moved forward in rapid motion. Furthermore, when the on-off valve 11 is closed due to the movement of the moving body 7 moving forward, the amount of liquid flowing through the working flow path 9 is reduced to the flow rate control valve 1.
2, the liquid cylinder 1 is stopped or retreated by the pressurized liquid, and the movable body 7 is intermittently advanced in a slow manner. Then, by cutting a workpiece (not shown) with a cutting tool 6 provided on the moving body 7, fine chips are obtained.

After cutting of the workpiece (not shown) is completed, the main switching valve 8
When it is operated to the right switching position, the working flow path 10 is connected to the liquid tank 27, the working flow path 9 is connected to the pressure source 13, and the liquid cylinder 1 is operated by the pressure liquid supplied to the working chamber 4, and the moving body Fast forward 7 backwards. At this time, the rotational direction switching valve 15 is not supplied with pressure liquid and is stopped.

With such intermittent feed operation, the rotation direction switching valve 15
Since it is rotated using a part of the pressure liquid supplied to the liquid cylinder 1, it is not necessary to separately provide an electric circuit for controlling the intermittent feed of the liquid cylinder 1, and reliable intermittent feed control can be obtained. At the same time, the installation can be done easily by simply adding the rotational direction switching valve 15 and the liquid pressure intensifier 36 to the existing device. Further, the rotation direction switching valve 15 rotates the internal gear 20 and the external gear 21 by supplying pressure liquid, and the switching grooves 28 and 29 on the external surface of the internal gear 20 allow the pilot load port 30 to be connected to the pilot supply port 31 and the pilot discharge port. 32, the rotation mechanism and the valve mechanism can be integrated, resulting in a compact configuration. Further, since the intermittent stopping or retracting operation is performed by the pressure increasing liquid discharged from the liquid pressure intensifier 36, the intermittent stopping or retracting operation can be reliably achieved and accurate control can be performed.

In this way, the present invention installs a flow rate control valve in the working flow path on the discharge side of the liquid cylinder when feeding and controlling the moving body, and also connects the flow direction switching valve to the working flow path on the supply side. The rotational direction switching valve is provided by rotatably fitting an internal gear into a fitting hole in the housing, and an external gear is eccentrically internally engaged with the internal gear, so that the pressure liquid in the supply side working flow path is controlled. The internal gear is provided so that the internal gear and the external gear are rotated by the supply of the internal gear, and the inner surface of the fitting hole into which the internal gear fits is provided with a pilot load port, a pilot supply port connected to the supply side, and a pilot exhaust port connected to the low pressure side. In addition to providing an open outlet, a switching groove is formed on the outer surface of the internal gear so that the pilot load port can be switched between the pilot supply port and the pilot discharge port by the rotation of the internal gear, and a piston is provided inside. The valve is slidably inserted to form a large diameter working chamber and a small diameter pressure intensifying chamber, and the working chamber is communicated with a pilot load port of a rotary switching valve to switch between a pilot supply port and a pilot discharge port of the pilot load port. A liquid pressure intensifier is provided so that a piston reciprocates each time the communication is made to discharge the pressure boosting liquid from the pressure boosting chamber, and the flow path through which the pressure boosting liquid discharged from the liquid pressure booster flows becomes the discharge side of the liquid cylinder. By connecting the liquid cylinder upstream of the flow rate control valve in the flow path and operating the liquid cylinder intermittently, it is possible to eliminate the need for an electric circuit for controlling the intermittent feed of the liquid cylinder, and to obtain reliable intermittent feed control.

In addition, the rotation direction switching valve rotates the internal gear and the external gear by supplying pressure liquid, and the pilot load port is switched and communicated with the pilot supply port and the pilot discharge port by the switching groove on the external surface of the internal gear. The rotation mechanism and valve mechanism can be integrated, resulting in a compact configuration. Further, since the intermittent stopping or retracting operation is performed by the pressurized liquid discharged from the liquid pressure intensifier, intermittent stopping or retracting operation can be achieved and accurate control can be achieved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a control circuit diagram partially showing a feed control device in cross section, and FIG.
FIG. 3 is a side view of the rotational direction switching valve as viewed from the side of FIG. 1; FIG. 1... Liquid cylinder, 9, 10... Working flow path,
15...Rotation direction switching valve, 20...Internal gear, 2
1... External gear, 28, 29... Switching groove, 30...
...Pilot load port, 31...Pilot supply port, 32...Pilot discharge port, 36...Liquid pressure booster.

Claims (1)

[Scope of utility model registration request] When controlling the feeding of a moving object, a flow control valve is installed in the working flow path on the discharge side of the liquid cylinder, and
A rotational direction switching valve is provided connected to the working flow path on the supply side, and the rotational direction switching valve rotatably fits the internal gear into the fitting hole in the housing, and also separates the external gear from the internal gear. The internal gear and the external gear are provided so that they are internally meshed with each other so that they are rotated by the supply of pressure fluid from the supply side working flow path, and the inner surface of the fitting hole into which the internal gear is inserted is provided with a pilot load port. A pilot supply port connected to the supply side and a pilot discharge port connected to the low pressure side are opened, and a pilot load port is switched to a pilot supply port and a pilot discharge port by rotation of the internal gear on the external surface of the internal gear. A switching groove is recessed for communication, and a piston is slidably inserted into the inside to form a large-diameter working chamber and a small-diameter pressure increasing chamber, and the working chamber is communicated with the pilot load port of the rotary switching valve. A liquid pressure intensifier is provided so that the piston reciprocates and discharges the pressurized liquid from the pressure intensification chamber every time the pilot load port is switched between the pilot supply port and the pilot discharge port, and the pressure intensifier is discharged from the liquid pressure intensifier. A feed control device configured to connect a flow path through which liquid flows upstream of a flow rate control valve of an operating flow path on the discharge side of the liquid cylinder to intermittently operate the liquid cylinder.