WO2019109826A1

WO2019109826A1 - Negative-pressure balance weight device for machine tool

Info

Publication number: WO2019109826A1
Application number: PCT/CN2018/117370
Authority: WO
Inventors: 戴琳; 李莉; 江涛; 颜荣旋; 叶寒; 刘华
Original assignee: 江西佳时特精密机械有限责任公司
Priority date: 2017-12-05
Filing date: 2018-11-26
Publication date: 2019-06-13
Also published as: CN107838744A

Abstract

A negative-pressure balance weight device for a machine tool comprises a machine tool body (1) and a gravity shaft (3) disposed on the machine tool body (1). The machine tool body (1) is provided with an air cylinder (4) used for supporting the gravity shaft (3). A body/a telescopic shaft of the air cylinder (4) is connected to the machine tool body (1). The telescopic shaft/the body of the air cylinder (4) is connected to the top end of the gravity shaft (3). The air cylinder (4) is a negative-pressure air cylinder. The negative-pressure balance weight device for a machine tool also comprises a negative-pressure supply source used for supplying a constant negative pressure to the air cylinder (4). The negative-pressure balance weight device for a machine tool has a high response speed, so that the machine tool can reach a high-speed cutting requirement.

Description

Machine tool negative pressure counterweight

Technical field

The invention relates to the technical field of numerical control machine tools, in particular to a negative pressure weighting device for a machine tool.

Background technique

In order to improve the stability of the gravity axis of CNC machine tools during high-speed movement, the gravity axis of CNC machine tools is guaranteed to have high precision when moving at high speed. The gravity axis of the CNC machine tool moves up and down. Due to the inertia, the stability of the weight of the gravity axis directly affects the accuracy of its movement, especially in the micro-scale machine tools.

At present, the commonly used weighting methods for domestic CNC machine tools are as follows:

1. Counterweight weight: simple structure and low failure rate; it uses the weight of the weight body to offset the weight of the gravity axis unit, thereby improving the fast moving speed of the machine tool, but the weight body will appear when the high speed and acceleration are large. Part of the weight loss, when the balance of gravity axis effect will be reduced, the response characteristics are poor, not suitable for high-speed cutting.

2. Cylinder counterweight: See Figure 1, Figure 2, which transmits the air pressure to the cylinder and then to the gravity axis unit, which gives the gravity shaft an upward force to achieve the effect of balancing the gravity axis. Therefore, the speed of the movement of the gravity axis of the machine tool is appropriately increased. The heavier weight is equipped with a significant speed to increase the movement of the gravity axis. However, when the gravity axis is cut at high speed, the high gravity will occur at high frequency up and down reciprocating motion, and in the process of reciprocating the gravity axis, the cylinder is accompanied by The upper and lower reciprocating motions, because of the high frequency, when the cylinder moves in the telescopic axial direction, the gas of the cylinder needs to be quickly discharged, and when the gas in the cylinder is discharged, the gas will be in the cylinder due to the limited internal space of the cylinder. The gas port (the area inside the circle in Fig. 2) gathers to cause gas blockage. This phenomenon will affect the corresponding speed of the cylinder, causing the gravity axis to be stuck, so it still cannot meet the requirements of high speed and high precision.

3. Hydraulic counterweight: The principle of counterweight is consistent with the cylinder weight, but the fluidity of the hydraulic medium is poor, which makes the weight of this weight method poor, and is not suitable for high-speed cutting.

4. Nitrogen counterweight: This counterweight method uses the principle of the accumulator to transfer the gas to the oil, and controls the balance cylinder to move up and down with the gravity axis to achieve higher speed and higher precision machining. Nitrogen counterweights do not require external power equipment to save energy, and are currently the most widely used on the market. However, when the gravity axis moves up and down, the pressure in the energy storage tank changes, causing the weight to be inaccurate, thereby affecting the machining accuracy and the stability of the machine tool.

Summary of the invention

The object of the present invention is to overcome the deficiencies of the prior art and adapt to the actual needs, and to provide a negative pressure weighting device for a machine tool with novel structural design, fast response speed and high speed cutting.

In order to achieve the object of the present invention, the technical solution adopted by the present invention is:

A machine tool negative pressure counterweight device is designed, which comprises a machine tool body and a gravity shaft disposed on the machine body, wherein the machine body is provided with a cylinder for supporting a gravity shaft, and the cylinder body/telescopic shaft is connected with the machine body, the cylinder The telescopic shaft/body is coupled to the top end of the gravity shaft; the cylinder is a negative pressure cylinder, and further includes a negative pressure supply source for providing a constant negative pressure to the cylinder, and a stable negative pressure is provided to the cylinder by a negative pressure supply source The weight axis is weighted by a cylinder.

Preferably, the negative pressure supply source comprises a negative pressure pump connected to the cylinder through a gas pipe.

Preferably, an energy storage tank is further included, the cylinder is connected to the energy storage tank, and the vacuum pump is also connected to the energy storage tank.

Preferably, a first one-way valve is disposed on the pipeline between the energy storage tank and the negative pressure pump.

Preferably, the cylinders are two. At this time, the negative pressure ports of the two cylinders communicate with the energy storage tank through the pipeline.

Preferably, a double vent valve is disposed on the pipeline between the negative pressure ports of the two cylinders, and a second one-way valve is disposed on the gas pipe between the energy storage tank and the adjacent cylinder;

Preferably, the first check valve, the second check valve, and the double vent valve are all solenoid valves, and further include a PLC controller, wherein the first check valve, the second check valve, and the double vent valve are both Connected to the PLC controller;

Preferably, the method further includes an electronic negative pressure gauge disposed on the energy storage tank; the electronic negative pressure gauge is also correspondingly connected to the PLC controller.

Preferably, an electronic negative pressure gauge is respectively disposed on the negative pressure port ends of the two cylinders, and at this time, two electronic negative pressure gauges on the negative pressure port end are also connected with the PLC controller. .

The beneficial effects of the invention are:

The design can carry out the weight support of the gravity shaft by the principle of negative pressure. By this principle, the accumulation of gas in the cylinder cavity can be avoided, especially when the telescopic shaft on the cylinder is retracted, the positive pressure cylinder in the prior art can be solved. The phenomenon of gas accumulation and gravity axis card tonnage can meet the requirements of high speed and high precision cutting.

DRAWINGS

Figure 1 is a schematic diagram of the principle of using a cylinder arrangement;

2 is a schematic diagram showing the principle of gas accumulation and clogging in the existing cylinder;

Figure 3 is a schematic structural diagram of the present design;

Figure 4 is a schematic diagram of the application structure of the present design;

Figure 5 is a schematic diagram of the principle structure of the present design;

In the figure: 1. machine body; 2. gravity axis; 3. linear motor; 4. cylinder; 5. cylinder cavity; 6. cylinder exhaust pipe; 7. air pipe; 8. energy storage tank; One-way valve; 10. Negative pressure pump; 11. PLC controller; 12, 15, 16. Electronic negative pressure gauge; 13. Second check valve; 14. Double vent valve.

Detailed ways

The present invention is further described below in conjunction with the accompanying drawings and embodiments:

Embodiment 1: A machine tool negative pressure counterweight device, see FIG. 3; it comprises a machine tool body 1, a gravity shaft 3 disposed on the machine tool body 1, and a gravity shaft 3 connected to the machine tool body 1 by a linear motor, the machine tool body The upper 1 is provided with a cylinder 4 for supporting a gravity shaft, and the body/telescopic shaft of the cylinder 4 is connected to the machine body, and the telescopic shaft/body of the cylinder is connected to the top end of the gravity shaft (the above is a prior art).

Specifically, the cylinder 4 in the present design is a negative pressure cylinder, and further includes a negative pressure supply source that supplies a constant negative pressure to the cylinder 4, and provides a stable negative pressure to the cylinder through the negative pressure supply source to pass through the cylinder. The gravity axis is weighted.

The negative pressure supply source includes a negative pressure pump, an energy storage tank, the cylinder is connected to the energy storage tank, and the negative pressure pump is also connected to the energy storage tank.

The negative pressure pump and the energy storage tank can provide a constant negative pressure to the cylinder, and the negative pressure can realize the support of the cylinder on the telescopic shaft of the cylinder, and the tension of the cylinder on the gravity axis can be achieved by the negative pressure as much as possible. It is equal to the gravity of the gravity axis, which can reduce the load capacity of the linear motor, reduce the load of the motor and improve the sensitivity of the motor. Moreover, due to the use of the negative pressure cylinder, the cylinder inside the cylinder can avoid the gas quickly recovering from the telescopic shaft. When gas accumulation and clogging occur, the rapid response capability of the gravity axis is improved, and the requirements for high-speed and high-precision cutting can be achieved.

Further, in the present design, a first check valve 9 is disposed on the pipeline between the energy storage tank 8 and the negative pressure pump 10. The capacity of the energy storage tank can be retained by the closing of the first one-way valve 9, so that the negative pressure pump can provide a stable negative pressure to the cylinder through the energy storage tank, and if the negative pressure in the energy storage tank When the first check valve 9 is opened, the first check valve 9 is opened, and the negative pressure pump is opened to close the first check valve 9 after the negative pressure in the energy storage tank reaches the requirement.

Embodiment 2, referring to FIG. 4 to FIG. 5, the same points as Embodiment 1 are not described again, except that the cylinders 4 are two, and at this time, the negative pressure ports of the two cylinders 4 pass. After the pipeline is connected, it is connected to the energy storage tank 8.

Further, a double vent valve 14 is disposed on the pipeline between the negative pressure ports of the two cylinders, and a second one-way valve 13 is disposed on the air pipe between the energy storage tank 8 and the adjacent cylinder 4; The first check valve, the second check valve and the double vent valve are all solenoid valves, and further comprise a PLC controller, wherein the first check valve, the second check valve and the double vent valve are both The PLC controller is connected; and further includes an electronic negative pressure gauge 12 disposed on the energy storage tank; the electronic negative pressure gauge is also connected to the PLC controller.

Further, an electronic negative pressure gauge 15 and 16 are respectively disposed on the negative pressure port ends of the two cylinders 4. At this time, the two electronic negative pressure gauges 15 and 16 located at the negative pressure port end are also The PLC controller 11 is correspondingly connected.

The above two cylinders work at the same time. When the two cylinders are working, the second check valve and the double vent valve are all closed, and the electronic negative pressure gauges 12, 15, 16 are in real-time monitoring state, if the energy storage tank is negative When the pressure is lower than the preset value, the pressure is adjusted by the negative pressure pump; and if the negative pressure in one of the cylinders is lower than the preset value, at this time, the double vent valve is opened to cause the negative pressure in the two cylinders to self-adjust, when When the negative pressure value in the two cylinders is within the allowable error range after the double vent valve is opened, the double vent valve is closed again; and when the negative pressure value in the two cylinders after the double vent valve is opened is no longer allowed within the error range, The second one-way valve is opened and adjusted by the energy storage tank, and when the negative pressure value in the two cylinders reaches a preset value, the second one-way valve and the double vent valve are closed again; the above-mentioned negative pressure value monitoring The monitoring is carried out by the corresponding electronic negative pressure gauge, and the closing and opening of the first check valve, the second check valve and the double vent valve are controlled by the PLC controller, and the first check valve and the second one-way Valve and double vent valve, electronic negative pressure gauge and PLC control The connection is all prior art. Furthermore, the control of the first check valve, the second check valve and the double vent valve by the PLC controller is also achievable in the prior art, and the embodiment does not perform it again. More details.

The embodiments of the present invention are disclosed in the preferred embodiments, but are not limited thereto, and those skilled in the art can easily understand the spirit of the present invention and make various extensions and changes according to the above embodiments. However, it is within the scope of the invention as long as it does not depart from the spirit of the invention.

Claims

A machine tool negative pressure weighting device comprises a machine tool body, a gravity shaft disposed on the machine body, the machine body is provided with a cylinder for supporting a gravity shaft, and the cylinder body/telescopic shaft is connected with the machine body, the cylinder The telescopic shaft/body is coupled to the top end of the gravity shaft; the cylinder is a negative pressure cylinder, and further includes a negative pressure supply source for providing a constant negative pressure to the cylinder, and the cylinder is stabilized by a negative pressure supply source The negative pressure is used to weight the gravity shaft through the cylinder.
A machine tool negative pressure counterweight according to claim 1, wherein said negative pressure supply source comprises a negative pressure pump connected to the cylinder via a gas pipe.
A machine tool negative pressure counterweight according to claim 2, further comprising an energy storage tank, said cylinder being coupled to said energy storage tank, said vacuum pump being also coupled to said energy storage tank.
The negative pressure weighting device for a machine tool according to claim 3, wherein a first one-way valve is disposed on the pipe between the energy storage tank and the negative pressure pump.
The machine tool negative pressure counterweight apparatus according to claim 4, wherein the cylinders are two, and at this time, the negative pressure ports of the two cylinders communicate with the energy storage tank through the pipeline.
A negative pressure weighting device for a machine tool according to claim 5, wherein a line between the negative pressure ports of the two cylinders is provided with a double venting valve, and the gas pipe between the energy storage tank and the adjacent cylinder Providing a second check valve;

The first check valve, the second check valve, and the double vent valve are all solenoid valves, and further include a PLC controller, wherein the first check valve, the second check valve, and the dual vent valve are all PLC controller connection;

The utility model further comprises an electronic negative pressure gauge disposed on the energy storage tank; the electronic negative pressure gauge is also connected to the PLC controller.
The negative pressure weighting device for a machine tool according to claim 6, wherein an electronic negative pressure gauge is respectively disposed on the negative pressure port ends of the two cylinders, and at this time, two of the negative pressure port ends are disposed. An electronic negative pressure gauge is also connected to the PLC controller.