Differential hydraulic circuit of sewing machine

Abstract

The utility model belongs to the technical field of hydraulic control of non-ferrous metal strip finishing equipment, and particularly discloses a differential hydraulic circuit of a sewing machine, which comprises a pump station and a differential control valve group. The differential control valve set comprises a piston cavity oil inlet two-way cartridge valve, a piston cavity oil return two-way cartridge valve, a piston rod cavity oil inlet two-way cartridge valve, a piston rod cavity oil return two-way cartridge valve, a piston cavity control electromagnetic directional valve, a rod cavity control electromagnetic directional valve and an unloading control electromagnetic directional valve, wherein the piston cavity control electromagnetic directional valve and the rod cavity control electromagnetic directional valve are used for logic control. The piston cavity oil inlet two-way cartridge valve and the piston rod cavity oil inlet two-way cartridge valve are opened at the same time, the piston cavity oil return two-way cartridge valve and the piston rod cavity oil return two-way cartridge valve are closed at the same time, pressure oil enters two cavities of the sewing oil cylinder at the same time, the pressure oil in the piston rod cavity returns to the piston cavity due to the area difference of the two cavities, and rapid die assembly of the sewing oil cylinder is achieved. And rapid die assembly can be realized without selecting a too large hydraulic pump and a motor with relatively high power, so that the enterprise cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydraulic control of non-ferrous metal strip finishing equipment, and specifically discloses a differential hydraulic circuit for a sewing machine. Background Technique

[0002] The non-ferrous metal strip finishing equipment includes a tension leveling unit, a cleaning unit, etc. The production line is relatively long, and the initial threading is very troublesome, time-consuming and laborious. To avoid repeated threading, currently, the sewing machine stitching scheme is generally adopted. After the previous coil of strip is completed with the production process, the tail of the previous coil of strip is stitched together with the head of the next coil of strip, so as to realize the smooth threading of the next coil of strip and improve the production efficiency. Usually, the stitching function of the sewing machine is completed by two hydraulic cylinders. Its working process includes actions such as rapid die closing, slow die closing, pressure holding, and returning. Because the two stitching oil cylinders have a relatively large cylinder diameter, a relatively large flow rate is required to quickly close the die, which requires a hydraulic pump with a relatively large flow rate and a driving motor with a relatively large power to achieve, resulting in relatively high purchase costs and usage costs. Summary of the Invention

[0003] To solve the problems in the background technique, the utility model discloses a differential hydraulic circuit for a sewing machine, which includes a pumping station and a differential control valve group. During operation, the oil inlet two-way cartridge valves of the piston chamber and the piston rod chamber are opened simultaneously, and the oil return two-way cartridge valves of the piston chamber and the piston rod chamber are closed simultaneously. Pressure oil enters both chambers of the sewing oil cylinder at the same time. By using the pressure difference between the piston chamber and the piston rod chamber, the pressure oil in the piston rod chamber returns to the piston chamber. When realizing rapid die closing, it is not necessary to select a hydraulic pump that is too large and a motor with a relatively large power to achieve rapid die closing, thereby reducing the enterprise cost.

[0004] To achieve the above invention purpose, the utility model adopts the following technical solution:

[0005] A differential hydraulic circuit for a sewing machine includes a pumping station and a sewing oil cylinder, and further includes a differential control valve group. The differential control valve group includes an oil inlet two-way cartridge valve for the piston chamber, an oil return two-way cartridge valve for the piston chamber, an oil inlet two-way cartridge valve for the piston rod chamber, and an oil return two-way cartridge valve for the piston rod chamber. The B ports of the oil inlet two-way cartridge valve for the piston chamber and the oil inlet two-way cartridge valve for the piston rod chamber are respectively connected to the P port of the pumping station, and the B ports of the oil return two-way cartridge valve for the piston chamber and the oil return two-way cartridge valve for the piston rod chamber are respectively connected to the T port of the pumping station;

[0006] The A port of the two-way cartridge valve for piston chamber oil inlet is respectively connected to the piston chamber of the stitching oil cylinder, the A port of the two-way cartridge valve for piston chamber oil return, and the A port of the unloading control solenoid directional valve. The B port of the two-way cartridge valve for piston chamber oil inlet is also connected to the P port of the plug chamber control solenoid directional valve through a shuttle valve inside its cover plate. The A port of the plug chamber control solenoid directional valve is connected to the upper chamber of the spool of the two-way cartridge valve for piston chamber oil inlet, and the B port of the plug chamber control solenoid directional valve is connected to the upper chamber of the spool of the two-way cartridge valve for piston chamber oil return. The T ports of the plug chamber control solenoid directional valve and the unloading control solenoid directional valve are respectively connected to the B port of the two-way cartridge valve for piston chamber oil return;

[0007] The A port of the two-way cartridge valve for piston rod chamber oil inlet is respectively connected to the piston rod chamber of the stitching oil cylinder and the A port of the two-way cartridge valve for piston rod chamber oil return. The B port of the two-way cartridge valve for piston rod chamber oil inlet is also connected to the P port of the rod chamber control solenoid directional valve through a shuttle valve inside its cover plate. The A port of the rod chamber control solenoid directional valve is connected to the upper chamber of the spool of the two-way cartridge valve for piston rod chamber oil inlet, and the B port of the rod chamber control solenoid directional valve is connected to the upper chamber of the spool of the two-way cartridge valve for piston rod chamber oil return. The T port of the rod chamber control solenoid directional valve is connected to the T port of the pump station;

[0008] A plug chamber pressure measuring joint and a pressure relay are arranged at intervals on the pipeline adjacent to the piston chamber of the stitching oil cylinder, and a rod chamber pressure measuring joint is arranged on the pipeline adjacent to the piston rod chamber of the stitching oil cylinder. The pressure relay is used to monitor the clamping pressure in real time, and the plug chamber pressure measuring joint and the rod chamber pressure measuring joint are respectively used to connect a pressure gauge to detect the pressure in the piston chamber of the stitching oil cylinder or the piston rod chamber of the stitching oil cylinder.

[0009] Further, in the differential hydraulic circuit of the stitching machine, a throttle is arranged at the A port of the unloading control solenoid directional valve.

[0010] Compared with the prior art, the beneficial effects of the present utility model are:

[0011] The differential hydraulic circuit of the stitching machine disclosed by the present utility model includes a pump station and a differential control valve group. The differential control valve group includes a two-way cartridge valve for piston chamber oil inlet, a two-way cartridge valve for piston chamber oil return, a two-way cartridge valve for piston rod chamber oil inlet, a two-way cartridge valve for piston rod chamber oil return, a plug chamber control solenoid directional valve and a rod chamber control solenoid directional valve for logic control, and an unloading control solenoid directional valve for unloading. During rapid die closing, the two-way cartridge valve for piston chamber oil inlet and the two-way cartridge valve for piston rod chamber oil inlet are opened simultaneously, and the two-way cartridge valve for piston chamber oil return and the two-way cartridge valve for piston rod chamber oil return are closed simultaneously. Pressure oil enters both chambers of the stitching oil cylinder at the same time. Due to the area difference between the two chambers, the pressure oil in the piston rod chamber returns to the piston chamber, realizing the rapid die closing of the stitching oil cylinder. It is possible to achieve rapid die closing without selecting a too large hydraulic pump and a motor with a large power, reducing the purchase cost and use cost of the enterprise. Description of the Drawings

[0012] Figure 1It is a schematic diagram of the differential hydraulic circuit of the sewing machine of the present utility model;

[0013] In the above figure: 1 - Pump station; 2 - Two-way cartridge valve for piston chamber oil inlet; 3 - Two-way cartridge valve for piston chamber oil return; 4 - Two-way cartridge valve for piston rod chamber oil inlet; 5 - Two-way cartridge valve for piston rod chamber oil return; 6 - Solenoid directional control valve for piston chamber control; 7 - Solenoid directional control valve for piston rod chamber control; 8 - Solenoid directional control valve for unloading control; 9 - Pressure measuring joint for piston rod chamber; 10 - Pressure measuring joint for piston chamber; 11 - Pressure relay; 12 - Sewing oil cylinder. Specific embodiments

[0014] In order to better understand the present utility model, the content of the present utility model will be further clearly described below in conjunction with embodiments. However, the protection scope of the present utility model is not limited to the following embodiments. In the following description, a large number of specific details are given to provide a more thorough understanding of the present utility model. However, it is obvious to those skilled in the art that the present utility model can be implemented without one or more of these details.

[0015] Combined with the attached Figure 1 , a differential hydraulic circuit of a sewing machine according to the present utility model is described in detail, which includes a pump station 1 and a sewing oil cylinder 12, and also includes a differential control valve group. Since the flow rate of the sewing machine 12 is relatively large, the present utility model adopts a two-way cartridge valve integrated control circuit. The differential control valve group includes a two-way cartridge valve 2 for piston chamber oil inlet, a two-way cartridge valve 3 for piston chamber oil return, a two-way cartridge valve 4 for piston rod chamber oil inlet, and a two-way cartridge valve 5 for piston rod chamber oil return. The B ports of the two-way cartridge valve 2 for piston chamber oil inlet and the two-way cartridge valve 4 for piston rod chamber oil inlet are respectively connected to the P port of the pump station 1. The B ports of the two-way cartridge valve 3 for piston chamber oil return and the two-way cartridge valve 5 for piston rod chamber oil return are respectively connected to the T port of the pump station 1;

[0016] The A port of the two-way cartridge valve 2 for piston chamber oil inlet is respectively connected to the piston chamber of the sewing oil cylinder 12, the A port of the two-way cartridge valve 3 for piston chamber oil return, and the A port of the solenoid directional control valve 8 (YV3) for unloading control. The B port of the two-way cartridge valve 2 for piston chamber oil inlet is also connected to the P port of the solenoid directional control valve 6 (YV1) for piston chamber control through a shuttle valve in its cover plate. The A port of the solenoid directional control valve 6 for piston chamber control is connected to the upper chamber of the spool of the two-way cartridge valve 2 for piston chamber oil inlet. The B port of the solenoid directional control valve 6 for piston chamber control is connected to the upper chamber of the spool of the two-way cartridge valve 3 for piston chamber oil return. The T ports of the solenoid directional control valve 6 for piston chamber control and the solenoid directional control valve 8 for unloading control are respectively connected to the B port of the two-way cartridge valve 3 for piston chamber oil return;

[0017] It should be noted here that: when the plug cavity control solenoid directional valve 6 is de-energized, the valve is in the middle position. The pressure oil P port of the plug cavity control solenoid directional valve 6 is communicated with the A port and the B port, and the return oil T port is not communicated. At this time, the pressure oil at the A port of the plug cavity control solenoid directional valve 6 acts on the upper end of the spool of the piston cavity oil inlet two-way cartridge valve 2, and the pressure oil at the B port of the plug cavity control solenoid directional valve 6 acts on the upper end of the spool of the piston cavity return oil two-way cartridge valve 3. The piston cavity oil inlet two-way cartridge valve 2 and the piston cavity return oil two-way cartridge valve 3 are in the closed state; when the a-end electromagnet of the plug cavity control solenoid directional valve 6 is energized, the solenoid valve is in the left position, the pressure oil P port of the plug cavity control solenoid directional valve 6 is communicated with the B port, and the A port is communicated with the return oil T port; when the b-end electromagnet of the plug cavity control solenoid directional valve 6 is energized, the solenoid valve is in the right position, the pressure oil P port of the plug cavity control solenoid directional valve 6 is communicated with the A port, and the B port of the plug cavity control solenoid directional valve 6 is communicated with the return oil T port;

[0018] The A port of the piston rod cavity oil inlet two-way cartridge valve 4 is respectively connected to the piston rod cavity of the sewing oil cylinder 12 and the A port of the piston rod cavity return oil two-way cartridge valve 5. The B port of the piston rod cavity oil inlet two-way cartridge valve 4 is also connected to the P port of the rod cavity control solenoid directional valve 7 (YV2) through a shuttle valve in its cover plate. The A port of the rod cavity control solenoid directional valve 7 is connected to the upper cavity of the spool of the piston rod cavity oil inlet two-way cartridge valve 4, the B port of the rod cavity control solenoid directional valve 7 is connected to the upper cavity of the spool of the piston rod cavity return oil two-way cartridge valve 5, and the T port of the rod cavity control solenoid directional valve 7 is connected to the T port of the pump station 1;

[0019] It should be noted here that: when the electromagnet of the rod cavity control solenoid directional valve 7 is de-energized, the solenoid valve is in the right position, the pressure oil P port of the rod cavity control solenoid directional valve 7 is communicated with the A port, and the B port of the rod cavity control solenoid directional valve 7 is communicated with the return oil T port; when the electromagnet of the rod cavity control solenoid directional valve 7 is energized, the solenoid valve is in the left position, the pressure oil P port of the rod cavity control solenoid directional valve 7 is communicated with the B port, and the A port of the rod cavity control solenoid directional valve 7 is communicated with the return oil T port;

[0020] A plug cavity pressure measuring joint 10 and a pressure relay 11 are arranged at intervals on the pipeline adjacent to the piston cavity of the sewing oil cylinder 12. A rod cavity pressure measuring joint 9 is arranged on the pipeline adjacent to the piston rod cavity of the sewing oil cylinder 12. The pressure relay 11 is used to monitor the clamping pressure in real time. The plug cavity pressure measuring joint 10 and the rod cavity pressure measuring joint 9 are respectively used to connect a pressure gauge to detect the pressure of the piston cavity of the sewing oil cylinder 12 or the piston rod cavity of the sewing oil cylinder 12.

[0021] As an optional design, it is preferred to set a throttle in the A port of the unloading control solenoid directional valve 8 in the differential hydraulic circuit of the sewing machine to prevent too fast pressure relief from generating impact, vibration and noise.

[0022] The working process of the differential hydraulic circuit of the sewing machine of the present utility model is as follows:

[0023] The pressure oil port P and the oil return port T of the pumping station 1 are connected to the differential control valve group through pipelines. The pressure oil enters the differential control valve group and acts on the port B of the two-way cartridge valve 2 for the piston chamber oil inlet and the port B of the two-way cartridge valve 4 for the piston rod chamber oil inlet. When the electromagnetic directional valves are all de-energized, the pressure oil reaches the port P of the piston chamber control electromagnetic directional valve 6 and the rod chamber control electromagnetic directional valve 7 through the shuttle valve in the cover plates of the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 4 for the piston rod chamber oil inlet. Then, the pressure oil acts on the upper end of the valve cores of the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 4 for the piston rod chamber oil inlet through the electromagnetic directional valves, so that the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 4 for the piston rod chamber oil inlet are both in the closed state, and the stitching oil cylinder 12 has no action. The purpose of the shuttle valve in the cover plates of the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 4 for the piston rod chamber oil inlet is to ensure reliable closing of the cartridge valve;

[0024] When the a-end electromagnet (YV1a) of the piston chamber control electromagnetic directional valve 6 and the rod chamber control electromagnetic directional valve 7 (YV2) are both energized, the pressure oil acts on the upper end of the valve core of the two-way cartridge valve 3 for the piston chamber oil return through the solenoid valve YV1, closing the two-way cartridge valve 3 for the piston chamber oil return. And the upper end of the valve core of the two-way cartridge valve 2 for the piston chamber oil inlet is in the oil return state. The pressure oil opens the valve core of the two-way cartridge valve 2 for the piston chamber oil inlet through the port B of the two-way cartridge valve 2 for the piston chamber oil inlet to reach the port A and then enters the piston chamber of the stitching oil cylinder 12. At the same time, after YV2 is energized, similarly, the two-way cartridge valve 5 for the piston rod chamber oil return is closed, and the two-way cartridge valve 4 for the piston rod chamber oil inlet is opened. The pressure oil enters the piston rod chamber of the stitching oil cylinder 12 through the two-way cartridge valve 4 for the piston rod chamber oil inlet. Since the area of the piston chamber is larger than that of the piston rod chamber, the thrust generated by the oil pressure in the piston chamber is greater than the thrust of the oil pressure in the piston rod chamber. In this way, the oil in the piston chamber and the piston rod chamber is combined to push the piston of the stitching oil cylinder 12 to rise, and the stitching oil cylinder 12 quickly closes the mold;

[0025] Before approaching the mold closing position, the proximity switch installed on the equipment sends a signal to de-energize the rod chamber control electromagnetic directional valve 7, closing the two-way cartridge valve 4 for the piston rod chamber oil inlet and opening the two-way cartridge valve 5 for the piston rod chamber oil return. The oil in the piston rod chamber returns to the oil tank of the pumping station 1 through the two-way cartridge valve 5 for the piston rod chamber oil return. The piston chamber control electromagnetic directional valve 6 remains in the energized state, and the pressure oil continues to enter the piston chamber of the stitching oil cylinder 12 through the two-way cartridge valve 2 for the piston chamber oil inlet, and the stitching oil cylinder 12 slowly closes the mold;

[0026] The pressure relay 11 monitors the mold closing pressure in real time. When the pressure no longer increases, it indicates that the mold closing is in place. The pressure relay 11 sends a signal indicating that the mold closing is in place. The piston chamber control electromagnetic directional valve 6 (YV1) is de-energized and in the middle position of the valve. The pressure oil acts on the valve cores of the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 3 for the piston chamber oil return through the solenoid valve YV1 respectively, closing the two-way cartridge valve 2 for the piston chamber oil inlet and the two-way cartridge valve 3 for the piston chamber oil return. The pressure oil in the piston chamber is sealed inside, and the stitching machine is in the pressure holding position;

[0027] When the set pressure holding time is reached, the unloading control solenoid directional valve 8 (YV3) is energized, and the sewing machine is depressurized;

[0028] When the pressure relay 11 detects the set depressurization completion signal, the pressure relay 11 sends out the depressurization completion signal, and the b-end electromagnet (YV1b) of the plugging cavity control solenoid directional valve 6 and the rod cavity control solenoid directional valve 7 are energized simultaneously. The two-way cartridge valve 4 for the rod piston cavity to inlet oil opens, and the two-way cartridge valve 5 for the rod piston cavity to return oil closes. The pressure oil enters the rod piston cavity of the sewing oil cylinder 12 through the two-way cartridge valve 4 for the rod piston cavity to inlet oil. At the same time, the two-way cartridge valve 3 for the piston cavity to return oil opens, and the two-way cartridge valve 2 for the piston cavity to inlet oil closes. The oil in the piston cavity returns to the oil tank of the pump station 1 through the two-way cartridge valve 3 for the piston cavity to return oil, and the sewing oil cylinder 12 returns.

[0029] To clearly show the relationship between the energization and de-energization of the solenoid valve electromagnets and the actions of each oil cylinder, it is concisely shown in the following table:

[0030]

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Any other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A differential hydraulic circuit for a sewing machine, comprising a pump station and a sewing cylinder, characterized in that: It also includes a differential control valve group, which includes a piston chamber oil inlet two-way cartridge valve, a piston chamber oil return two-way cartridge valve, a piston rod chamber oil inlet two-way cartridge valve and a piston rod chamber oil return two-way cartridge valve, the B ports of the piston chamber oil inlet two-way cartridge valve and the piston rod chamber oil inlet two-way cartridge valve are respectively connected to the pump station P port, and the piston chamber oil return two-way cartridge valve and the piston rod chamber oil return two-way cartridge valve B ports are respectively connected to the pump station T port; The A port of the piston chamber oil inlet two-way cartridge valve is respectively connected to the piston chamber of the sewing cylinder, the A port of the piston chamber oil return two-way cartridge valve and the A port of the unloading control electromagnetic reversing valve, the B port of the piston chamber oil inlet two-way cartridge valve is also connected to the P port of the plug chamber control electromagnetic reversing valve through the shuttle valve in its cover plate, the A port of the plug chamber control electromagnetic reversing valve is connected to the valve core upper chamber of the piston chamber oil inlet two-way cartridge valve, the B port of the plug chamber control electromagnetic reversing valve is connected to the valve core upper chamber of the piston chamber oil return two-way cartridge valve, and the T ports of the plug chamber control electromagnetic reversing valve and the unloading control electromagnetic reversing valve are respectively connected to the B port of the piston chamber oil return two-way cartridge valve; The A port of the piston rod chamber oil inlet two-way cartridge valve is respectively connected to the piston rod chamber of the sewing oil cylinder and the A port of the piston rod chamber oil return two-way cartridge valve, the B port of the piston rod chamber oil inlet two-way cartridge valve is also connected to the P port of the rod chamber control electromagnetic reversing valve through the shuttle valve in its cover plate, the A port of the rod chamber control electromagnetic reversing valve is connected to the valve core upper chamber of the piston rod chamber oil inlet two-way cartridge valve, the B port of the rod chamber control electromagnetic reversing valve is connected to the valve core upper chamber of the piston rod chamber oil return two-way cartridge valve, and the T port of the rod chamber control electromagnetic reversing valve is connected to the T port of the pump station; Plug cavity pressure measuring joints and pressure relays are arranged at intervals on the pipeline adjacent to the sewing cylinder piston cavity, and a rod cavity pressure measuring joint is arranged on the pipeline adjacent to the sewing cylinder piston rod cavity. The pressure relay is used for real-time monitoring of the mold clamping pressure, and the plug cavity pressure measuring joint and the rod cavity pressure measuring joint are respectively used for connecting pressure gauges to detect the pressure of the sewing cylinder piston cavity or the sewing cylinder piston rod cavity.

2. The differential hydraulic circuit of a sewing machine according to claim 1, characterized in that: A throttle is provided at port A of the unloading control electromagnetic reversing valve.

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