CN-121988721-A - Control method and system for reducing injection starting impact of die casting machine

Abstract

The invention discloses a control method and a system for reducing injection starting impact of a die casting machine, wherein the method comprises the steps of controlling a front cavity of an injection cylinder to execute a multi-stage pre-holding pressure process before an injection starting instruction is sent; the pre-pressure-building process at least comprises a first pressure-raising stage for controlling the action of the back-hammer valve group and a second pressure-raising stage for controlling the action of the front-hammer valve group, and after the pre-pressure-building process is finished, the injection starting action is executed.

Inventors

• XU JIANHUA
• CHEN LIE
• ZHANG HAO
• ZHENG PEI
• DONG CHAOQI
• ZHANG JINPENG

Assignees

• 宁波保税区海天智胜金属成型设备有限公司

Dates

Publication Date

20260508

Application Date

20260130

Claims (10)

1. 1. A control method for reducing injection start-up shock of a die casting machine, the method comprising: before the injection starting instruction is sent out, controlling a front cavity of an injection oil cylinder to execute a multi-stage pre-holding pressure process; The pre-holding pressure process at least comprises a first pressure increasing stage for controlling the action of the back hammer valve group and a second pressure increasing stage for controlling the action of the front hammer valve group; and after the pre-holding pressure process is finished, executing the injection starting action.
2. 2. The method of claim 1, wherein the first pressure increasing stage is configured to increase the pressure of the front chamber to a first pressure value, and wherein the second pressure increasing stage is configured to increase the pressure of the front chamber from the first pressure value to a predetermined target pressure threshold P.
3. 3. The method according to claim 2, wherein the target pressure threshold P is calculated based on an accumulator pressure P1 of the injection system, an injection ram cross-sectional area S1, and a cross-sectional area S2 of the injection rod.
4. 4. The method of claim 3, further comprising presetting a safety upper limit for the target pressure threshold P; when the calculated P value exceeds the safety upper limit value, the actually used target pressure value is defined as the safety upper limit value.
5. 5. The method according to claim 2, characterized in that in the second boost phase the output of the hydraulic pump is controlled so that hydraulic oil enters the front chamber smoothly with a controlled flow until the pressure reaches the target pressure threshold P.
6. 6. The method according to claim 2, further comprising a pressure stabilization phase after the pressure of the front chamber reaches the target pressure threshold P; In the pressure stabilization stage, the pressure of the front cavity is maintained at the target pressure threshold value P for a preset stabilization time, and then the injection starting action is executed.
7. 7. The method of claim 1, wherein the pressure in the front chamber is monitored by a pressure sensor directly disposed at the outlet of the injection cylinder, or calculated by a main system configuration pressure sensor in combination with a hydraulic circuit model.
8. 8. The control system for reducing the injection starting impact of the die casting machine is characterized by comprising a controller, a back hammer valve group and a front hammer valve group which are connected with the front cavity of an injection cylinder, and a pressure monitoring unit; the controller is configured to perform the method of any one of claims 1 to 7.
9. 9. The system of claim 8, wherein the pressure monitoring unit is a pressure sensor disposed at an outlet of the injection ram or a pressure sensor configured for a main system.
10. 10. A computer readable storage medium, on which a computer program is stored, characterized in that the method according to any one of claims 1 to 7 is implemented when the computer program is executed by a processor.

Description

Control method and system for reducing injection starting impact of die casting machine Technical Field The application relates to the technical field of control of die casting machines, in particular to a control method and a control system for reducing injection starting impact of a die casting machine. Background The die casting machine is industrial equipment for obtaining castings by pressing molten metal into a die cavity at high speed through pressure and cooling and molding, and is widely applied to the fields of automobiles, machinery, electronics and the like. The injection system is a core component of the die casting machine, and the starting performance of the injection system directly influences the quality of castings and the stability of equipment. In the injection starting process of a conventional die casting machine, as the energy accumulator is released instantly when the inlet directional valve is opened, strong pulse type hydrodynamic force can be generated to push the hammer head to accelerate instant plunging, so that starting impact is formed. Impact during injection starting is easy to cause gas coiling, fluctuation and even splashing of a metal solution in a charging barrel, casting defects such as air holes, shrinkage cavities, cold partitions and the like are generated, the quality of products is influenced, and the consistency of injection technology is influenced. In order to solve the problem of starting impact, the prior art adopts the modes of arranging a proportional valve or a small-caliber directional valve at the injection inlet for cooperative control, adding a pressurizing cylinder or a pressurizing pump at the injection outlet for pressurizing, adding a buffer device and the like if pursuing performance, but has obvious limitations that the cost is high, the structure of an injection part of a die casting machine becomes more complex, and the prior art adopts a section type front cavity pressurizing mode if pursuing economy, the pressurizing pressure is not high, the starting is still impacted, or the hammer head moves forwards too much in the pressurizing process, so that the soup and the injection effect are influenced. Therefore, there is a need for a control method that is simple in design and structure, low in cost, and preferably free of cost, and significantly improves the injection start impact to solve the above-mentioned problems. Disclosure of Invention In order to solve the problems, the embodiment of the application provides a control method and a control system for reducing the injection starting impact of a die casting machine, which can realize stable starting without complex hardware modification and through control optimization and reduce the injection starting impact of the die casting machine. In a first aspect, an embodiment of the present application provides a control method for reducing injection start impact of a die casting machine, where the method includes: before the injection starting instruction is sent out, controlling a front cavity of an injection oil cylinder to execute a multi-stage pre-holding pressure process; The pre-holding pressure process at least comprises a first pressure increasing stage for controlling the action of the back hammer valve group and a second pressure increasing stage for controlling the action of the front hammer valve group; and after the pre-holding pressure process is finished, executing the injection starting action. Preferably, the first pressure increasing stage is used for increasing the pressure of the front cavity to a first pressure value, and the second pressure increasing stage is used for increasing the pressure of the front cavity from the first pressure value to a preset target pressure threshold value P. Preferably, the target pressure threshold P is calculated based on the accumulator pressure P1 of the injection system, the sectional area S1 of the injection cylinder, and the sectional area S2 of the injection rod. The specific calculation formula is P=P1×S1/(S1-S2). Preferably, the method further comprises the step of presetting a safety upper limit value of the target pressure threshold value P; when the calculated P value exceeds the safety upper limit value, the actually used target pressure value is defined as the safety upper limit value. Preferably, in the second boost stage, the output of the hydraulic pump is controlled so that hydraulic oil smoothly enters the front chamber at a controlled flow rate until the pressure reaches the target pressure threshold P. Preferably, after the pressure of the front cavity reaches the target pressure threshold P, a pressure stabilization stage is further included; In the pressure stabilization stage, the pressure of the front cavity is maintained at the target pressure threshold value P for a preset stabilization time, and then the injection starting action is executed. Preferably, the pressure of the front cavity is monitored by a pressure sen