A pilot control oil circuit for the injection flow valve of a die-casting machine

Abstract

A pilot control oil circuit for a die-casting machine's injection flow valve comprises a fast accumulator, a boost accumulator, a fast proportional valve, a boost proportional valve, a first one-way valve, a second one-way valve, a first high-pressure filter, and a second high-pressure filter. The inlet of the first one-way valve is connected to the oil port of the fast accumulator, the inlet of the second one-way valve is connected to the oil port of the boost accumulator, the inlet of the first high-pressure filter is connected to the outlet of the first one-way valve and the outlet of the second one-way valve, respectively, and the outlet of the first high-pressure filter is connected to the pilot valve of the fast proportional valve, the pilot valve of the boost proportional valve, and the inlet of the second high-pressure filter, respectively. The present invention simultaneously draws pressure oil from the fast accumulator and the boost accumulator into the pilot control oil circuit of the injection flow valve. As long as the pressure oil in any accumulator is not completely released, the pilot control oil circuit of the injection flow valve can be ensured to be full of pressure oil, the injection flow valve is in a controlled state, and the machine will not malfunction. The invention has the characteristics of simple structure, reliable performance, and low manufacturing cost.

Description

Technical Field

[0001] The invention relates to a die-casting machine, in particular to a pilot control oil circuit of an injection flow valve of the die-casting machine. Background Art

[0002] The injection flow valves of large or high-end die-casting machines are generally configured as proportional valves or servo valves (for example, Chinese patent document CN208057587U, a hydraulic system for a die-casting machine, disclosed on November 6, 2018). However, these valves have relatively high requirements for oil cleanliness, so they all require a separate pilot oil circuit to control the valves. Currently, there are three main schemes for setting up pilot oil circuits: the first scheme is to set up an independent hydraulic oil source to provide pressure oil to the pilot oil circuit; the second scheme is to set up an independent filter for each valve and draw pressure oil from its own accumulator to supply the pilot oil circuit of each valve; the third scheme is to centrally draw pressure oil from a fast accumulator or a boost accumulator to supply the pilot oil circuits of all injection flow valves. All three schemes have drawbacks: Schemes 1 and 2 are complex and costly; in Scheme 3, if the accumulator that draws oil is empty or has low pressure, the flow control valve of the other accumulator will open due to the lack of pilot pressure oil control, and the pressure oil in the accumulator will be released, causing malfunction and even personal injury and property damage.

[0003] Therefore, further improvements are necessary. Summary of the Invention

[0004] The purpose of the present invention is to provide a pilot control oil circuit for a die casting machine injection flow valve having a simple and reasonable structure, reliable performance, low manufacturing cost, convenient debugging and maintenance, and strong practicality, so as to overcome the shortcomings of the prior art.

[0005] A pilot control oil circuit of a die-casting machine injection flow valve designed for this purpose includes a fast accumulator, a boost accumulator, a fast proportional valve, and a boost proportional valve. It is characterized in that it also includes a first one-way valve, a second one-way valve, a first high-pressure filter, and a second high-pressure filter. The inlet of the first one-way valve is connected to the oil port of the fast accumulator, the inlet of the second one-way valve is connected to the oil port of the boost accumulator, the inlet of the first high-pressure filter is respectively connected to the outlet of the first one-way valve and the outlet of the second one-way valve, and the outlet of the first high-pressure filter is respectively connected to the pilot valve of the fast proportional valve, the pilot valve of the boost proportional valve, and the inlet of the second high-pressure filter.

[0006] It also includes a quick exhaust servo valve and a third one-way valve. The second high-pressure filter outlet is connected to the third one-way valve inlet, and the third one-way valve outlet is connected to the quick exhaust servo valve pilot valve.

[0007] An energy accumulator is provided on a pipeline connecting the outlet of the third one-way valve and the pilot valve of the quick exhaust servo valve.

[0008] A pressure gauge is also provided on the pipeline connecting the outlet of the third one-way valve and the pilot valve of the quick exhaust servo valve.

[0009] It also includes an oil tank, and a stop valve connected to the oil tank is also provided on the pipeline connecting the outlet of the third one-way valve and the pilot valve of the quick exhaust servo valve.

[0010] The filtering accuracy of the second high-pressure filter is higher than that of the first high-pressure filter.

[0011] The pilot control oil circuit of the injection flow valve of the die-casting machine of the present invention draws the pressure oil of the pilot control oil circuit of the injection flow valve from the fast accumulator and the boost accumulator at the same time. As long as the pressure oil of any accumulator is not completely released, it can ensure that the pilot control oil circuit of the injection flow valve is full of pressure oil, the injection flow valve is in a controlled state, and will not cause malfunction of the machine. It has the characteristics of simple and reasonable structure, reliable performance and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a pilot control oil circuit diagram of the injection flow valve of a die-casting machine in one embodiment of the present invention. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] See also Figure 1 The pilot control oil circuit of the injection flow valve of the die-casting machine includes a fast accumulator 1, a boost accumulator 2, a fast proportional valve 3, a boost proportional valve 4, a first one-way valve 6, a second one-way valve 7, a first high-pressure filter 8 and a second high-pressure filter 9. The inlet of the first one-way valve 6 is connected to the oil port of the fast accumulator 1, the inlet of the second one-way valve 7 is connected to the oil port of the boost accumulator 2, the inlet of the first high-pressure filter 8 is respectively connected to the outlet of the first one-way valve 6 and the outlet of the second one-way valve 7, and the outlet of the first high-pressure filter 8 is respectively connected to the pilot valve of the fast proportional valve 3, the pilot valve of the boost proportional valve 4 and the inlet of the second high-pressure filter 9.

[0015] It also includes a quick exhaust servo valve 5 and a third one-way valve 10 . The outlet of the second high-pressure filter 9 is connected to the inlet of the third one-way valve 10 , and the outlet of the third one-way valve 10 is connected to the pilot valve of the quick exhaust servo valve 5 .

[0016] An accumulator 11 is provided on the pipeline connecting the outlet of the third one-way valve 10 and the pilot valve of the quick exhaust servo valve 5 .

[0017] A pressure gauge 12 is also provided on the pipeline connecting the outlet of the third one-way valve 10 and the pilot valve of the quick exhaust servo valve 5 .

[0018] It also includes an oil tank 14 , and a stop valve 13 connected to the oil tank 14 is provided on the pipeline connecting the outlet of the third one-way valve 10 and the pilot valve of the quick exhaust servo valve 5 .

[0019] The filtering accuracy of the second high-pressure filter 9 is higher than that of the first high-pressure filter 8 . After two filtrations, cleaner pressure oil is provided to the quick exhaust servo valve 5 .

[0020] The third one-way valve 10 is used to prevent the frequent and rapid action of the pilot valve of the quick exhaust servo valve 5 from impacting the first high-pressure filter 8 , the second high-pressure filter 9 , the quick proportional valve 3 and the boost proportional valve 4 .

[0021] The accumulator 11 is provided for storing oil to avoid abnormal oil supply because the distance between the fast accumulator 1 and the boost accumulator 2 and the quick exhaust servo valve 5 is relatively far.

[0022] The pressure gauge 12 is convenient for observing whether the pressure oil in the pilot control oil circuit of the injection flow valve is normal.

[0023] The stop valve 13 is used to release the pressure oil in the pilot control oil circuit of the injection flow valve during maintenance.

[0024] Working principle of the pilot control oil circuit of the injection flow valve of the die casting machine:

[0025] By respectively providing a first one-way valve 6 at the oil port of the fast accumulator 1 and a second one-way valve 7 at the oil port of the boost accumulator 2, the pressure oil of the two accumulator groups is introduced into the first high-pressure filter 8. If the pressure oil of any accumulator is higher, the pressure oil is drawn from the accumulator to provide the pilot control oil circuit of the injection flow valve, ensuring that the injection flow valve is in a controlled state before the pressure of any accumulator is completely released, thereby preventing the injection flow valve from opening out of control due to lack of pressure oil control due to the incomplete release of the accumulator pressure oil, causing the accumulator pressure oil to enter the injection cylinder or the boost cylinder, pushing the injection piston rod to extend, and causing personal injury and property damage.

[0026] The above is a preferred embodiment of the present invention, which illustrates and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A pilot control oil circuit for a die-casting machine injection flow valve, comprising a fast accumulator (1), a boost accumulator (2), a fast proportional valve (3), and a boost proportional valve (4), characterized in that: The invention also includes a first one-way valve (6), a second one-way valve (7), a first high-pressure filter (8) and a second high-pressure filter (9), wherein the inlet of the first one-way valve (6) is connected to the oil port of the fast accumulator (1), the inlet of the second one-way valve (7) is connected to the oil port of the boost accumulator (2), the inlet of the first high-pressure filter (8) is respectively connected to the outlet of the first one-way valve (6) and the outlet of the second one-way valve (7), and the outlet of the first high-pressure filter (8) is respectively connected to the pilot valve of the fast proportional valve (3), the pilot valve of the boost proportional valve (4) and the inlet of the second high-pressure filter (9); It also includes a quick exhaust servo valve (5) and a third one-way valve (10), the outlet of the second high-pressure filter (9) is connected to the inlet of the third one-way valve (10), and the outlet of the third one-way valve (10) is connected to the pilot valve of the quick exhaust servo valve (5); An accumulator (11) is provided on a pipeline connecting the outlet of the third one-way valve (10) and the pilot valve of the quick exhaust servo valve (5); The filtering accuracy of the second high-pressure filter (9) is higher than the filtering accuracy of the first high-pressure filter (8).

2. The pilot control oil circuit of the injection flow valve of the die casting machine according to claim 1, characterized in that: A pressure gauge (12) is also provided on the pipeline connecting the outlet of the third one-way valve (10) and the pilot valve of the quick exhaust servo valve (5).

3. The pilot control oil circuit of the injection flow valve of the die casting machine according to claim 1, characterized in that: It also includes an oil tank (14), and a stop valve (13) connected to the oil tank (14) is provided on the pipeline connecting the outlet of the third one-way valve (10) and the pilot valve of the quick exhaust servo valve (5).

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