A hydraulic control device for replacing shear blades

Abstract

A hydraulic control device for replacing a shear blade relates to the field of strip steel processing. The hydraulic control device for replacing a shear blade comprises a plurality of upper shear blade locking hydraulic cylinders for locking an upper shear blade, a plurality of upper anti-collision block hydraulic cylinders for pushing an upper anti-collision block to limit the upper shear blade, a plurality of lower shear blade locking hydraulic cylinders for locking a lower shear blade, a plurality of lower shear blade anti-collision block hydraulic cylinders for pushing a lower anti-collision block to limit the lower shear blade, a first stop valve, a second stop valve, a third stop valve, a fourth stop valve, a quick connector and a first two-position three-way reversing valve connected thereto. One end of the first stop valve, the second stop valve, the third stop valve, and the fourth stop valve are respectively connected to the rodless chambers of each upper shear blade locking hydraulic cylinder, each upper anti-collision block hydraulic cylinder, each lower shear blade locking hydraulic cylinder, and each lower shear blade anti-collision block hydraulic cylinder through pipelines, and the other ends are respectively connected to the quick connectors. The hydraulic control device for replacing a shear blade facilitates the judgment and processing of a stop valve failure and the replacement of a shear blade.

Description

Technical Field

[0001] The present application relates to the field of strip steel processing devices, and in particular to a hydraulic control device for shear blade replacement. Background Art

[0002] The production process characteristics of hot-rolled strip steel will make the head of the heated strip steel into a tongue shape and the tail into a dovetail shape after being rolled by the rough rolling mill. These irregular head and tail structures of the strip steel are not conducive to the rolling of the finishing mill. In order to ensure the continuous and stable production, the strip steel produced by the rough rolling is usually cut and removed by a flying shear before entering the finishing mill. The finishing flying shear consists of the main drive, frame, shear blade, intermediate roller table and other parts. Among them, the replacement of the shear blade is a daily operation of the finishing flying shear equipment maintenance.

[0003] The shear blade of the flying shear is fixed by hydraulic cylinders, including: upper shear blade locking hydraulic cylinders (five), upper shear blade anti-collision block hydraulic cylinders (two), lower shear blade locking hydraulic cylinders (four), lower shear blade anti-collision block hydraulic cylinders (two), a total of thirteen hydraulic cylinders. When replacing the shear blade of the flying shear, the operator needs to manually connect four sets of shear blade replacement hydraulic control pipelines, and then control the corresponding valves to open all the above four sets of hydraulic cylinders, and finally pull out the shear blade.

[0004] During the actual on-site replacement of the shear blade, problems such as long operation time and many sudden failures often occur. It often takes eight hours to replace a shear blade, and the operation can only be arranged within the long-term maintenance plan once a month. The frequency of replacing the shear blade once a month is too low, which is not conducive to maintaining the condition of the shear blade. Summary of the invention

[0005] The purpose of the present application is to provide a hydraulic control device for shear blade replacement, which simplifies the control circuit, facilitates the judgment and processing of faults of the reversing valve and the hydraulic cylinder, and reduces the impact of related faults on shear blade replacement.

[0006] The embodiment of the present application is implemented as follows:

[0007] The embodiment of the present application provides a hydraulic control device for replacing a shear blade, which includes a shear blade fixing control circuit composed of multiple upper shear blade locking hydraulic cylinders for locking the upper shear blade, multiple upper anti-collision block hydraulic cylinders for pushing the upper anti-collision block to limit the upper shear blade, multiple lower shear blade locking hydraulic cylinders for locking the lower shear blade, and multiple lower shear blade anti-collision block hydraulic cylinders for pushing the lower anti-collision block to limit the lower shear blade. The shear blade fixing control circuit also includes a valve group composed of a first stop valve, a second stop valve, a third stop valve and a fourth stop valve. One ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to the rodless chambers of each upper shear blade locking hydraulic cylinder, the rodless chambers of each upper anti-collision block hydraulic cylinder, the rodless chambers of each lower shear blade locking hydraulic cylinder and the rodless chambers of each lower shear blade anti-collision block hydraulic cylinder through pipelines. The other ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to one end of a quick connector with a one-way valve, and the other end of the quick connector is connected to a first two-position three-way reversing valve.

[0008] In some optional embodiments, a shear blade extraction hydraulic cylinder for assisting the extraction arm in dragging the shear blade is also included, and the rod chamber and rodless chamber of the shear blade extraction hydraulic cylinder are connected to the second two-position three-way reversing valve and the third two-position three-way reversing valve through oil pipes respectively.

[0009] In some optional embodiments, it also includes a bidirectional hydraulic motor for driving the extraction arm, and the two ends of the bidirectional hydraulic motor are connected to the A port and B port of the three-position four-way reversing valve through oil pipes, the P port of the three-position four-way reversing valve is connected to the three-way pressure reducing valve, and the B port of the three-way pressure reducing valve is connected to the inlet of the first two-position two-way solenoid valve.

[0010] In some optional implementation schemes, the P ports of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the inlet of the first two-position two-way solenoid valve, one end of the normally closed stop valve and one end of the one-way control valve, and the T ports of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the other end of the normally closed stop valve and the oil tank, and the oil tank is connected to the P port of the second two-position two-way solenoid valve, one end of the overflow valve and the other end of the one-way control valve through an oil pump, and the T port of the second two-position two-way solenoid valve and the other end of the overflow valve are also respectively connected to the oil tank.

[0011] In some optional implementation schemes, one end of the quick connector connected to the first two-position three-way reversing valve is also connected to the first pressure relay through a pipeline, the rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder are respectively connected to the second pressure relay and the third pressure relay through pipelines, the P port and T port of the three-position four-way reversing valve are respectively connected to the fourth pressure relay and the fifth pressure relay through pipelines, the T port of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the sixth pressure relay through pipelines, and the first pressure relay, the second pressure relay, the third pressure relay, the fourth pressure relay, the fifth pressure relay and the sixth pressure relay respectively establish electrical control interlocks with the second two-position two-way solenoid valve.

[0012] In some optional embodiments, it also includes a level meter for detecting the oil level in the oil tank and a thermometer for detecting the oil temperature in the oil tank.

[0013] The beneficial effect of the present application is that the hydraulic control device for shear blade replacement provided by the present application includes a shear blade fixing control circuit composed of multiple upper shear blade locking hydraulic cylinders for locking the upper shear blade, multiple upper anti-collision block hydraulic cylinders for pushing the upper anti-collision block to limit the upper shear blade, multiple lower shear blade locking hydraulic cylinders for locking the lower shear blade, and multiple lower shear blade anti-collision block hydraulic cylinders for pushing the lower anti-collision block to limit the lower shear blade. The shear blade fixing control circuit also includes a valve group composed of a first stop valve, a second stop valve, a third stop valve and a fourth stop valve. One ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to the rodless chambers of each upper shear blade locking hydraulic cylinder, the rodless chambers of each upper anti-collision block hydraulic cylinder, the rodless chambers of each lower shear blade locking hydraulic cylinder and the rodless chambers of each lower shear blade anti-collision block hydraulic cylinder through pipelines. The other ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to one end of a quick connector with a one-way valve, and the other end of the quick connector is connected to a first two-position three-way reversing valve. The hydraulic control device for shear blade replacement provided in the present application simplifies the control circuit, facilitates the judgment and processing of the reversing valve failure, and reduces the impact of the reversing valve and hydraulic cylinder failure on the shear blade replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of the structure of a hydraulic control device for shear blade replacement provided in an embodiment of the present application.

[0016] In the figure: 100, upper shear blade locking hydraulic cylinder; 110, upper anti-collision block hydraulic cylinder; 120, lower shear blade locking hydraulic cylinder; 130, lower shear blade anti-collision block hydraulic cylinder; 140, first stop valve; 150, second stop valve; 160, third stop valve; 170, fourth stop valve; 180, valve group; 190, quick connector; 200, first two-position three-way reversing valve; 210, shear blade extraction hydraulic cylinder; 220, second two-position three-way reversing valve; 230, third two-position three-way reversing valve; 240, bidirectional hydraulic motor; 25 0, three-position four-way reversing valve; 260, three-way pressure reducing valve; 270, first two-position two-way solenoid valve; 280, normally closed stop valve; 290, one-way control valve; 300, oil tank; 310, second two-position two-way solenoid valve; 320, overflow valve; 330, liquid level gauge; 340, thermometer; 350, oil pump; 400, first pressure relay; 410, second pressure relay; 420, third pressure relay; 430, fourth pressure relay; 440, fifth pressure relay; 450, sixth pressure relay. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0019] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0020] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0021] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0022] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] The features and performance of the hydraulic control device for shear blade replacement of the present application are further described in detail below in conjunction with the embodiments.

[0025] like Figure 1As shown, the embodiment of the present application provides a hydraulic control device for replacing a shear blade, which includes a shear blade fixing control circuit, the shear blade fixing control circuit includes five upper shear blade locking hydraulic cylinders 100 for locking the upper shear blade, two upper anti-collision block hydraulic cylinders 110 for pushing the upper anti-collision block to limit the upper shear blade, two lower shear blade locking hydraulic cylinders 120 for locking the lower shear blade and four lower shear blade anti-collision block hydraulic cylinders 130 for pushing the lower anti-collision block to limit the lower shear blade, and the shear blade fixing control circuit also includes a first stop valve 140, a second stop valve 150, a third stop valve 160 and a fourth stop valve 170. The valve group 180 is composed of the first stop valve 140, the second stop valve 150, the third stop valve 160, and the fourth stop valve 170, one end of which is connected to the rodless chamber of each upper shear blade locking hydraulic cylinder 100, the rodless chamber of each upper anti-collision block hydraulic cylinder 110, the rodless chamber of each lower shear blade locking hydraulic cylinder 120, and the rodless chamber of each lower shear blade anti-collision block hydraulic cylinder 130 through pipelines, and the other end of the first stop valve 140, the second stop valve 150, the third stop valve 160, and the fourth stop valve 170 is respectively connected to one end of a quick connector 190 with a one-way valve, and the other end of the quick connector 190 is connected to a first two-position three-way reversing valve 200. The hydraulic control device for replacing the shear blade also includes a shear blade extraction hydraulic cylinder 210 for assisting the extraction arm in dragging the shear blade. The rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder 210 are respectively connected to the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 through oil pipes; the hydraulic control device for replacing the shear blade also includes a bidirectional hydraulic motor 240 for driving the extraction arm. The two ends of the bidirectional hydraulic motor 240 are respectively connected to the A port and the B port of the three-position four-way reversing valve 250 through oil pipes, the P port of the three-position four-way reversing valve 250 is connected to the three-way pressure reducing valve 260, the B port of the three-way pressure reducing valve 260 is connected to the outlet of the first two-position two-way solenoid valve 270, and the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 2 The P port of 30 is respectively connected to the inlet of the first two-position two-way solenoid valve 270, one end of the normally closed stop valve 280 and one end of the one-way control valve 290, the T ports of the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 are respectively connected to the other end of the normally closed stop valve 280 and the oil tank 300, the oil tank 300 is connected to the P port of the second two-position two-way solenoid valve 310, one end of the overflow valve 320 and the other end of the one-way control valve 290 through the oil pump 350, the T port of the second two-position two-way solenoid valve 310 and the other end of the overflow valve 320 are also respectively connected to the oil tank 300, and the oil tank 300 is also connected to a level gauge 330 for detecting the internal oil level and a thermometer 340 for detecting the oil temperature in the oil tank 300.

[0026] One end of the quick connector 190 connected to the first two-position three-way reversing valve 200 is also connected to the first pressure relay 400 through a pipeline. The rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder 210 are respectively connected to the second pressure relay 410 and the third pressure relay 420 through pipelines. The P port and T port of the three-position four-way reversing valve 250 are respectively connected to the fourth pressure relay 430 and the fifth pressure relay 440 through pipelines. The T port of the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 are respectively connected to the sixth pressure relay 450 through pipelines. The first pressure relay 400, the second pressure relay 410, the third pressure relay 420, the fourth pressure relay 430, the fifth pressure relay 440 and the sixth pressure relay 450 respectively establish electrical control interlocking with the second two-position two-way solenoid valve 310.

[0027] The hydraulic control device for replacing the shear blade provided in the embodiment of the present application is connected to the rodless chamber of each upper shear blade locking hydraulic cylinder 100, the rodless chamber of each upper anti-collision block hydraulic cylinder 110, the rodless chamber of each lower shear blade locking hydraulic cylinder 120 and the rodless chamber of each lower shear blade anti-collision block hydraulic cylinder 130 through pipelines through one end of the first stop valve 140, the second stop valve 150, the third stop valve 160 and the fourth stop valve 170 respectively, and the first stop valve 140, the second stop valve 150, the third stop valve 160 and the fourth stop valve 170 are connected through a quick connector 190 with a one-way valve. 70 and the first two-position three-way reversing valve 200 can facilitate the user to synchronously control the actions of each upper shear blade locking hydraulic cylinder 100, each upper anti-collision block hydraulic cylinder 110, each lower shear blade locking hydraulic cylinder 120 and each lower shear blade anti-collision block hydraulic cylinder 130 by controlling the on-off of the first stop valve 140, the second stop valve 150, the third stop valve 160, the fourth stop valve 170 and the first two-position three-way reversing valve 200, thereby simplifying the control circuit, facilitating the operator to judge and deal with the failure of each stop valve, and reducing the impact of the reversing valve failure on the shear blade replacement.

[0028] The hydraulic control device for replacing the shear blade also includes a shear blade extraction hydraulic cylinder 210 for assisting the extraction arm in dragging the shear blade. The rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder 210 are respectively connected to the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 through oil pipes; the hydraulic control device for replacing the shear blade can assist in loosening the shear blade when the shear blade is in too tight contact with the base and the extraction arm cannot be pulled during the shear blade replacement process.

[0029] The hydraulic control device for replacing the shear blade also includes a bidirectional hydraulic motor 240 for driving the extraction arm. The two ends of the bidirectional hydraulic motor 240 are respectively connected to the A port and the B port of the three-position four-way reversing valve 250 through oil pipes. The P port of the three-position four-way reversing valve 250 is connected to the three-way pressure reducing valve 260. The B port of the three-way pressure reducing valve 260 is connected to the inlet of the first two-position two-way solenoid valve 270. The function of the hydraulic control device for replacing the shear blade is to quickly pull the shear blade out of and push it in the flying shear frame to facilitate the operator to replace the shear blade.

[0030] The P ports of the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 are respectively connected to the inlet of the first two-position two-way solenoid valve 270, one end of the normally closed stop valve 280 and one end of the one-way control valve 290, and the T ports of the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 are respectively connected to the other end of the normally closed stop valve 280 and the oil tank 300, and the oil tank 300 is connected to the second oil pump 350. The P port of the two-position two-way solenoid valve 310, one end of the relief valve 320 and the other end of the one-way control valve 290, the T port of the second two-position two-way solenoid valve 310 and the other end of the relief valve 320 are also connected to the oil tank 300 respectively. The oil tank 300 is also connected to a level gauge 330 for detecting the internal oil level and a thermometer 340 for detecting the oil temperature in the oil tank 300. The normally closed stop valve 280 can ensure that the system has the function of manual pressure relief, and the relief valve 320 can play an overload protection role.

[0031] One end of the quick connector 190 connected to the first two-position three-way reversing valve 200 is also connected to the first pressure relay 400 through a pipeline. The rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder 210 are respectively connected to the second pressure relay 410 and the third pressure relay 420 through pipelines. The P port and T port of the three-position four-way reversing valve 250 are respectively connected to the fourth pressure relay 430 and the fifth pressure relay 440 through pipelines. The T port of the first two-position three-way reversing valve 200, the second two-position three-way reversing valve 220 and the third two-position three-way reversing valve 230 are respectively connected to the sixth pressure relay 450 through pipelines. The first pressure relay 400, the second pressure relay 410, the third pressure relay 420, the fourth pressure relay 430, the fifth pressure relay 440 and the sixth pressure relay 450 respectively establish electrical control interlocking with the second two-position two-way solenoid valve 310. When the pressure value monitored by any of the above pressure relays exceeds its set value, the electromagnet of the second two-position two-way solenoid valve 310 is controlled to lose power to put the system into an automatic pressure relief state, thereby protecting the safety of related components of the control device.

[0032] The hydraulic control device for shear blade replacement provided in the embodiment of the present application simplifies the control circuit, makes it easier for operators to judge and handle the failure of each reversing valve, reduces the impact of reversing valve failure on shear blade replacement, reduces the cost and difficulty of organizing spare parts for system inspection and maintenance, and shortens the time required for shear blade replacement, making the arrangement of shear blade replacement operations more flexible, increasing the frequency of shear blade replacement, and facilitating the maintenance of the shear blade state.

[0033] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A hydraulic control device for replacing a shear blade, comprising a shear blade fixing control circuit, wherein the shear blade fixing control circuit comprises a plurality of upper shear blade locking hydraulic cylinders for locking the upper shear blade, a plurality of upper anti-collision block hydraulic cylinders for pushing the upper anti-collision block to limit the upper shear blade, a plurality of lower shear blade locking hydraulic cylinders for locking the lower shear blade, and a plurality of lower shear blade anti-collision block hydraulic cylinders for pushing the lower anti-collision block to limit the lower shear blade, characterized in that: The shear blade fixing control circuit also includes a valve group consisting of a first stop valve, a second stop valve, a third stop valve and a fourth stop valve. One ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to the rodless chamber of each upper shear blade locking hydraulic cylinder, the rodless chamber of each upper anti-collision block hydraulic cylinder, the rodless chamber of each lower shear blade locking hydraulic cylinder and the rodless chamber of each lower shear blade anti-collision block hydraulic cylinder through pipelines. The other ends of the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are respectively connected to one end of a quick connector with a one-way valve, and the other end of the quick connector is connected to a first two-position three-way reversing valve.

2. The hydraulic control device for shear blade replacement according to claim 1, characterized in that: It also includes a shear blade extraction hydraulic cylinder for assisting the extraction arm in dragging the shear blade. The rod chamber and rodless chamber of the shear blade extraction hydraulic cylinder are respectively connected to the second two-position three-way reversing valve and the third two-position three-way reversing valve through oil pipes.

3. The hydraulic control device for shear blade replacement according to claim 2, characterized in that: It also includes a bidirectional hydraulic motor for driving the extraction arm, the two ends of the bidirectional hydraulic motor are connected to the A port and the B port of the three-position four-way reversing valve through oil pipes, the P port of the three-position four-way reversing valve is connected to the three-way pressure reducing valve, and the B port of the three-way pressure reducing valve is connected to the inlet of the first two-position two-way solenoid valve.

4. The hydraulic control device for replacing the shear blade according to claim 3, characterized in that: The P ports of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the inlet of the first two-position two-way solenoid valve, one end of the normally closed stop valve and one end of the one-way control valve, and the T ports of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the other end of the normally closed stop valve and the oil tank, and the oil tank is connected to the P port of the second two-position two-way solenoid valve, one end of the overflow valve and the other end of the one-way control valve through an oil pump, and the T port of the second two-position two-way solenoid valve and the other end of the overflow valve are also respectively connected to the oil tank.

5. The hydraulic control device for shear blade replacement according to claim 4, characterized in that: One end of the quick connector connected to the first two-position three-way reversing valve is also connected to the first pressure relay through a pipeline. The rod chamber and the rodless chamber of the shear blade extraction hydraulic cylinder are respectively connected to the second pressure relay and the third pressure relay through pipelines. The P port and T port of the three-position four-way reversing valve are respectively connected to the fourth pressure relay and the fifth pressure relay through pipelines. The T port of the first two-position three-way reversing valve, the second two-position three-way reversing valve and the third two-position three-way reversing valve are respectively connected to the sixth pressure relay through pipelines. The first pressure relay, the second pressure relay, the third pressure relay, the fourth pressure relay, the fifth pressure relay and the sixth pressure relay respectively establish electrical control interlocking with the second two-position two-way solenoid valve.

6. The hydraulic control device for replacing the shear blade according to claim 4, characterized in that: It also includes a level meter for detecting the oil level in the oil tank and a thermometer for detecting the oil temperature in the oil tank.

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