Hydraulic control device for internal mixer

Abstract

The application relates to the technical field of rubber and plastic refining devices, and discloses a hydraulic control device of an internal mixer, which comprises an upper jack oil cylinder structure, a first loop structure, a second loop structure, an oil tank and an electro-hydraulic reversing valve, and is characterized in that the upper jack oil cylinder structure comprises a cross rod, a supporting rod, a piston, a sub-cylinder, a base, a vertical rod, a weight, a female cylinder and a box body; the base is symmetrical and is arranged on the two sides of the bottom of the box body; the female cylinder is arranged on the upside of the base; the sub-cylinder is arranged in the center of the female cylinder; the first pipeline is connected with the sub-cylinder by penetrating through the base; the supporting rod is hollow; the sub-cylinder penetrates through the inside of the supporting rod; the piston is fixedly connected with the tail end of the supporting rod; the piston is slidably connected with the sub-cylinder; the cross rod is arranged on the upper end of the supporting rod; the vertical rod is fixedly connected with the cross rod; and the weight is connected with the tail end of the vertical rod 106. The hydraulic control device of the internal mixer can exert constant pressure on rubber or plastic by the weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber mixing and plastic mixing device, in particular to a hydraulic control device of an internal mixer. BACKGROUND

[0002] The internal rubber mixing machine is referred to as the internal mixer, which is mainly used for mixing rubber and plastic and is widely applied. It is the first and extremely important step in the production process of the rubber and plastic industry. The mixing of rubber and plastic directly affects the quality of the finished product. The internal mixer plays a crucial role in the processing of rubber and plastic. The mixing process requires constant pressure on the rubber (plastic) at all times. Constant pressure can make the mixed rubber (plastic) better fused. The existing technology uses two upper jacks to pull a weight to apply constant pressure to the weight. Since the surface area of the weight is constant, the pressure on the contact surface between the weight and the mixed rubber (plastic) is constant.

[0003] There are two main ways to achieve constant pressure control in the hydraulic system. The first way is to use a servo valve closed-loop control to achieve it. The second way is to use a servo motor and a servo pump closed-loop control to achieve it. The first way often has faults such as high oil temperature, oil leakage, and valve core blockage during use, which results in high maintenance costs. The second way basically does not have the faults of the first way during use. However, at the initial stage of rubber (plastic) mixing, the mixed material is still hard, which will lift the weight to a large extent. When the hard mixed material is rotated to another angle under the action of the meshing teeth or the cutter, the weight will be hammered down instantly, which will cause a large impact and is not conducive to rubber (plastic) mixing. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a hydraulic control device of an internal mixer, which has the advantages of constant pressure when the weight is in action, and solves the problems in the background technology.

[0005] To achieve the purpose of constant pressure when the weight is in action, the present application provides the following technical solution: a hydraulic control device of an internal mixer, comprising an upper jack cylinder structure, a first circuit structure, a second circuit structure, an oil tank, and an electro-hydraulic reversing valve, wherein the upper jack cylinder structure comprises a crossbar, a support rod, a piston, a sub-cylinder, a base, a vertical rod, a weight, a female cylinder, and a tank body, the base is symmetrical and installed on both sides of the bottom of the tank body, the female cylinder is arranged on the upper side of the base, the sub-cylinder is arranged at the center of the female cylinder, the first pipeline is connected with the sub-cylinder through the base, the support rod is hollow, the sub-cylinder passes through the inside of the support rod, the piston is fixedly connected with the end of the support rod, the piston is slidably connected with the sub-cylinder, the crossbar is arranged on the upper end of the support rod, the vertical rod is fixedly connected with the crossbar, and the weight is connected with the end of the vertical rod.

[0006] Preferably, the first circuit structure is provided with a first pipeline, the beginning of the first pipeline is connected with the sub-cylinder, the first pipeline is provided with a first check valve, the lower pipeline is connected with the electro-hydraulic reversing valve, the pipeline passes through the electro-hydraulic reversing valve and is branched to be connected with a second check valve and a third check valve respectively, the lower pipeline of the second check valve is connected with the low-pressure pump, the lower pipeline of the third check valve is connected with the high-pressure pump and the first normally open electromagnetic overflow valve, the upper part of the high-pressure pump is provided with a servo motor, the pipeline branch between the second check valve and the low-pressure pump is connected with a third pipeline, the pipeline branch is provided with a second normally open electromagnetic overflow valve, the first normally open electromagnetic overflow valve and the oil tank are connected through the pipeline, and the end pipelines of the low-pressure pump and the high-pressure pump are combined and connected with the lower oil tank.

[0007] Preferably, the beginning of the second pipeline is connected with the upper side of the mother cylinder and communicates with the mother cylinder, the second pipeline is connected with a high-pressure accumulator and a first pressure sensor, the lower pipeline is connected with a third pipeline and an electro-hydraulic reversing valve respectively, the pipeline connected with the third pipeline is provided with an overflow valve, the second pipeline passes through the electro-hydraulic reversing valve and is connected with the third pipeline, the beginning of the third pipeline is connected with the bottom of the mother cylinder, and the end of the third pipeline is connected with the oil tank.

[0008] Preferably, the beginning of the second circuit structure is connected with the upper pipeline of the first check valve, the second circuit structure is sequentially provided with a first electromagnetic cut-off valve, a second pressure sensor, a low-pressure accumulator, a second electromagnetic cut-off valve, a back pressure check valve and an electromagnetic reversing valve, the end pipeline of the electromagnetic reversing valve is branched to be connected with a first throttle valve and a second throttle valve respectively, and the end of the second circuit structure is connected with the oil tank.

[0009] Preferably, the electro-hydraulic reversing valve comprises a main valve body, a main valve core and an electromagnetic coil, the lower part of the main valve body communicates with a first left lower pipeline, a left upper pipeline, a right lower pipeline, a right upper pipeline and a second left lower pipeline, the first left lower pipeline is connected with the second left lower pipeline, the main valve core is arranged in the main valve body and is in sliding connection with the main valve body 501, and the electromagnetic coil is fixedly connected with the left and right ends of the main valve core.

[0010] Preferably, the mixing process comprises the following steps:

[0011] Step one: the rotation speed of the control servo motor is used to control the horizontal rod of the upper jack cylinder structure of the internal mixer to drive the weight to rise quickly or slowly;

[0012] Step two: the control servo motor is in an appropriate rotation speed and the second throttle valve is adjusted to have a larger opening to control the weight of the upper jack cylinder structure of the internal mixer to descend quickly (fast forward);

[0013] Step three: control the ram slow down (work in) in the banbury mixer by controlling the servo motor at the appropriate speed and the second throttle valve to adjust the smaller opening.

[0014] Step four: according to the above step one to step three, control the banbury mixer to carry out rubber mixing or plastic mixing by controlling the servo motor speed and the second circuit structure switch to control the horizontal rod fast or slow up or down in the banbury mixer, and control the actual pressure size by the control unit to control the force stability of the ram to the rubber or plastic.

[0015] Preferably, the control unit is connected with the first pressure sensor and the servo motor.

[0016] Compared with the prior art, the present application provides a banbury mixer hydraulic control device, which has the following beneficial effects:

[0017] 1. The banbury mixer hydraulic control device uses the sub-cylinder oil inlet of the sub-mother cylinder to realize the lifting of the ram. Since the sub-cylinder has a small diameter, the hydraulic system only needs to output a small flow, thereby reducing the displacement and weight and volume of the hydraulic pump and improving the power density of the system.

[0018] 2. The banbury mixer hydraulic control device is provided with an accumulator between the hydraulic sub-mother cylinder and the oil tank, so that the back pressure always exists in the oil return path, and the hammering phenomenon does not occur during the pressing of rubber (plastic).

[0019] 3. The banbury mixer hydraulic control device controls the fast or slow down of the ram in the banbury mixer by controlling the servo motor speed and the second throttle valve to adjust the opening size, and controls the force stability of the ram to the rubber or plastic by controlling the actual pressure size. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0021] Figure 2 It is a schematic diagram of the oil cylinder structure of the present application;

[0022] Figure 3 It is a schematic diagram of the pipeline branch structure of the present application;

[0023] Figure 4 It is a schematic diagram of the pipeline branch structure of the present application;

[0024] Figure 5 It is a schematic diagram of the electro-hydraulic reversing valve structure of the present application;

[0025] Figure 6 It is a schematic diagram of the system principle of the present application;

[0026] Figure 7 It is a block diagram of the closed-loop control system of the present application.

[0027] In the figure:

[0028] The upper ram cylinder structure; 101, cross rod; 102, support rod; 103, piston; 104, sub-cylinder; 105, base; 106, vertical rod; 107, weight; 108, female cylinder; 109, tank;

[0029] The first circuit structure; 201, the first pipeline; 202, the second pipeline; 203, the third pipeline; 204, the high-pressure accumulator; 205, the first pressure sensor; 206, the first check valve; 207, the first normally open electromagnetic overflow valve; 208, the second check valve; 209, the third check valve; 210, the low-pressure pump; 211, the servo motor; 212, the high-pressure pump; 213, the second normally open electromagnetic overflow valve; 214, the electro-hydraulic reversing valve;

[0030] The second circuit structure; 301, the first electromagnetic cut-off valve; 302, the second pressure sensor; 303, the low-pressure accumulator; 304, the second electromagnetic cut-off valve; 305, the back pressure check valve; 306, the electromagnetic reversing valve; 307, the first throttle valve; 308, the second throttle valve;

[0031] The oil tank;

[0032] The electro-hydraulic reversing valve; 501, the main valve body; 502, the main valve core; 503, the electromagnetic coil; 504, the first left lower pipeline; 505, the left upper pipeline; 506, the right lower pipeline; 507, the right upper pipeline; 508, the second left lower pipeline. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. EMBODIMENT

[0034] The preferred embodiment of the hydraulic control device of the internal mixer provided by the present application is as follows Figures 1 to 5 As shown in the figure: the hydraulic control device of the internal mixer comprises an upper ram cylinder structure 1, a first circuit structure 2, a second circuit structure 3, an oil tank 4 and an electro-hydraulic reversing valve 5.

[0035] The hydraulic control device for the internal mixer of the present application comprises a crossbar 101, a support rod 102, a piston 103, a sub-cylinder 104, a base 105, a vertical rod 106, a weight 107, a female cylinder 108 and a box 109. The base 105 is symmetrical and installed on both sides of the bottom of the box 109. The female cylinder 108 is arranged on the upper side of the base 105, and the sub-cylinder 104 is arranged in the center of the female cylinder 108. The first pipeline 201 is connected to the sub-cylinder 104 through the base 105. The support rod 102 is hollow, and the sub-cylinder 104 passes through the inside of the support rod 102. The piston 103 is fixedly connected to the end of the support rod 102, and the piston 103 is slidably connected to the sub-cylinder 104. The crossbar 101 is arranged on the upper end of the support rod 102. The vertical rod 106 is fixedly connected to the crossbar 101, and the weight 107 is connected to the end of the vertical rod 106. The weight 107 below can place the rubber or plastic to be mixed.

[0036] Further, the first circuit structure 2 is provided with the first pipeline 201, the beginning of which is connected to the sub-cylinder 104. The first pipeline 201 is provided with the first one-way valve 206. The lower pipeline is connected to the electro-hydraulic reversing valve 5. The pipeline passes through the electro-hydraulic reversing valve 5 and is branched to be connected to the second one-way valve 208 and the third one-way valve 209. The second one-way valve 208 is connected to the low-pressure pump 210 through the pipeline below. The third one-way valve 209 is connected to the high-pressure pump 212 and the first normally open electromagnetic overflow valve 207 through the pipeline below. The servo motor 211 is arranged above the high-pressure pump 212. The pipeline branch between the second one-way valve 208 and the low-pressure pump 210 is connected to the third pipeline 203. The second normally open electromagnetic overflow valve 213 is arranged on the pipeline branch. The first normally open electromagnetic overflow valve 207 is connected to the oil tank 4 through the pipeline. The pipelines at the ends of the low-pressure pump 210 and the high-pressure pump 212 are merged and connected to the oil tank 4 below.

[0037] The second pipeline 202 is connected to the upper side of the female cylinder 108 and communicates with the female cylinder 108. The second pipeline 202 is connected to the high-pressure accumulator 204 and the first pressure sensor 205. The lower pipeline is connected to the third pipeline 203 and the electro-hydraulic reversing valve 5. The pipeline connected to the third pipeline 203 is provided with the overflow valve 214. The second pipeline 202 is connected to the third pipeline 203 after passing through the electro-hydraulic reversing valve 5. The beginning of the third pipeline 203 is connected to the bottom of the female cylinder 108. The end of the third pipeline 203 is connected to the oil tank 4.

[0038] The second loop structure 3 is connected at its beginning to the pipe above the first check valve 206. The second loop structure 3 is sequentially equipped with a first electromagnetic shut-off valve 301, a second pressure sensor 302, a low-pressure accumulator 303, a second electromagnetic shut-off valve 304, a back pressure check valve 305, and an electromagnetic reversing valve 306. The pipe at the end of the electromagnetic reversing valve 306 is split and connected to a first throttle valve 307 and a second throttle valve 308 respectively. The end of the second loop structure 3 is connected to the oil tank 4.

[0039] The electro-hydraulic directional valve 5 includes a main valve body 501, a main valve core 502, and an electromagnetic coil 503. The main valve body 501 is connected to the first lower left pipe 504, the upper left pipe 505, the lower right pipe 506, the upper right pipe 507, and the second lower left pipe 508. The main valve core 502 is disposed inside the main valve body 501 and is slidably connected to the main valve body 501. The electromagnetic coil 503 is fixedly connected to the left and right ends of the main valve core 502.

[0040] Depend on Figure 5 Specifically, the operation begins when the left and right electromagnetic coils 503 are energized, causing the main valve core 502 to move left and right within the main valve body 501. When not energized, the main valve core 502 is in the middle position, and the first lower left pipe 504, upper left pipe 505, lower right pipe 506, upper right pipe 507, and second lower left pipe 508 are not connected. When the left electromagnetic coil 503 is energized, the electro-hydraulic directional valve 5 is in the left position, and the main valve core 502 moves to the right. At this time, the upper left pipe 505 is connected to the lower right pipe 506, and the upper right pipe 507 is connected to the second lower left pipe. When the right electromagnetic coil 503 is energized, the electro-hydraulic directional valve 5 is in the right position, and the main valve core 502 moves to the left. The first lower left pipe 504 is connected to the upper left pipe 505, and the lower right pipe 506 is connected to the upper right pipe 507. Example

[0041] Based on Example 1, a preferred embodiment of the hydraulic control device for a mixing mill provided by the present invention is as follows: Figures 1 to 7 As shown: The specific implementation method includes the following steps:

[0042] Step 1: The speed of the servo motor 211 controls the crossbar 101 in the top cylinder structure 1 of the internal mixer to drive the pressure weight 107 to rise quickly or slowly.

[0043] Specifically, the first normally open electromagnetic relief valve 207 is in the working position, and the electro-hydraulic directional valve 5 is in the right position. The servo motor 211 is controlled to operate at an appropriate speed. Hydraulic oil flows from the high-pressure pump 212 through the third check valve 209, the electro-hydraulic directional valve 5, and the first check valve 206 to the sub-cylinder 104 of the upper jack cylinder structure 1. Simultaneously, hydraulic oil in the rod chamber of the mother cylinder 108 in the upper jack cylinder returns to the hydraulic oil tank 4 through the second pipe 202 at the top of the mother cylinder 108 and the electro-hydraulic directional valve 5. The extension of the crossbar 101 of the upper jack cylinder can be infinitely controlled by the speed of the servo motor 211. Since the diameter of the sub-cylinder 104 of the upper jack cylinder is very small, only a small flow rate is needed to achieve rapid extension. When the speed of the servo motor 211 is extremely low, the high-pressure pump 212 obtains very little hydraulic oil, resulting in a very small flow rate into the sub-cylinder 104 of the upper jack cylinder, thus allowing the crossbar 101 of the upper jack cylinder to extend slowly.

[0044] Step 2: The pressure bar 107 in the top cylinder structure 1 of the internal mixer is rapidly lowered (rapid advance) by controlling the servo motor 211 to an appropriate speed and adjusting the opening of the second throttle valve 308 to a larger size.

[0045] Specifically, the first normally open electromagnetic relief valve 207 and the second normally open electromagnetic relief valve 213 are in the working position, the electro-hydraulic directional valve 5 is in the left position, the electromagnetic directional valve 306 is in the right position, the first electromagnetic shut-off valve 301 and the second electromagnetic shut-off valve 304 are in the open state, the servo motor 211 is controlled to be at an appropriate speed, the hydraulic oil from the high-pressure pump 212 through the third check valve 209 and the hydraulic oil from the low-pressure pump 210 through the second check valve 208 are combined, and the oil flows through the electro-hydraulic directional valve 5 along the second pipeline 202 to the top hydrant. In cylinder mechanism 1, the rod chamber of the mother cylinder 108 is filled with hydraulic oil. At the same time, the hydraulic oil of the daughter cylinder 104 in the upper jack cylinder mechanism 1 flows out through the first pipe 201 and passes through the first solenoid shut-off valve 301, the second solenoid shut-off valve 304, the back pressure check valve 305, the solenoid directional valve 306, and the second throttle valve 308 in the second circuit structure 3 before returning to the oil tank 4. Because the opening of the second throttle valve 308 is relatively large, the hydraulic oil in the mother cylinder 108 in the upper jack cylinder structure 1 flows out quickly, and the piston 103 descends quickly, causing the crossbar 101 to retract quickly.

[0046] Step 3: The pressure bar 107 in the top cylinder structure 1 of the internal mixer is slowly lowered (working feed) by controlling the servo motor 211 to an appropriate speed and adjusting the opening of the second throttle valve 308 to a smaller size.

[0047] Specifically, the first normally open electromagnetic overflow valve 207 and the second normally open electromagnetic overflow valve 213 are in the working position, the electro-hydraulic reversing valve 5 is in the left position, the first electromagnetic shut-off valve 301 and the second electromagnetic shut-off valve 304 are in the open state, the control servo motor 211 is at an appropriate speed, the hydraulic oil from the high-pressure pump 212 through the third check valve 209 and the hydraulic oil from the low-pressure pump 210 through the second check valve 208 are combined, and then flow through the electro-hydraulic reversing valve 5 along the second pipeline 202 to the rod cavity of the mother cylinder 108 in the upper ram cylinder mechanism 1, at the same time, the hydraulic oil in the sub-cylinder 104 of the upper ram cylinder mechanism 1 flows out through the first pipeline 201, and then flows back to the oil tank 4 through the first electromagnetic shut-off valve 301, the second electromagnetic shut-off valve 304, the back pressure check valve 305, the electromagnetic reversing valve 306 and the second throttle valve 308 in the second circuit structure 3, and due to the small opening of the second throttle valve 308, the hydraulic oil in the mother cylinder 108 of the upper ram cylinder structure 1 slowly flows out, and the piston 103 slowly descends to drive the cross rod 101 to slowly retract.

[0048] Step four: according to the above steps one to three, the speed of the control servo motor 211 and the opening of the second circuit structure 3 are controlled to control the fast or slow upward or downward movement of the cross rod 101 in the upper ram cylinder structure 1, so as to control the rubber mixing or plastic mixing of the mixer, and the actual pressure is controlled by the control unit to control the stable force of the weight on the rubber or plastic.

[0049] Specifically, the first normally open electromagnetic overflow valve 207 is in the working position, the first electromagnetic shut-off valve 301 and the second electromagnetic shut-off valve 304 are in the open state, and the electro-hydraulic reversing valve 5 is in the left position. At this time, the sub-cylinder 104 of the upper ram cylinder structure 1 is connected with the low-pressure accumulator 303, and the internal pressure is the set pressure of the back pressure check valve 305. Since the diameter of the sub-cylinder 104 is very small, the volume change during mixing is very small, and the volume of the low-pressure accumulator 303 can be very small. The pressure change of the low-pressure accumulator 303 is very small under the maximum and minimum oil filling volume conditions. At this time, the sub-cylinder 104 of the upper ram cylinder structure 1 always has the back pressure provided by the low-pressure accumulator 303 in the working position, and when the load appears, the hammering phenomenon will not occur.

[0050] During rubber mixing or plastic mixing, the high-pressure pump 212 works, the low-pressure pump 210 is directly unloaded, the servo motor 211 drives the high-pressure pump 212 to rotate, and the pressure oil is provided to the rod cavity of the mother cylinder 108 in the upper ram cylinder structure 1. The first pressure sensor 205 feedbacks the pressure signal in real time , the control unit compares the set pressure with the feedback pressure , when and When not equal, real-time deviation is corrected by adjusting the rotating speed of servo motor 211, ensuring the pressure provided by the control unit is within the requirement of the set pressure, ensuring the pressure in the rubber mixing or plastic mixing process is constant, ensuring the up and down range of the cross bar in the top bolt oil cylinder structure 1 is uniform, and ensuring the force of the weight 107 on the rubber or plastic is stable.

[0051] It is to be noted that the relational terms herein, such as first and second, and the like, are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0052] While the embodiments of the application have been illustrated and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and alterations can be made therein without departing from the spirit and scope of the application, which is defined by the appended claims and their equivalents.

Claims

1. A hydraulic control device for an internal mixer, comprising an upper punch oil cylinder structure (1), a first circuit structure (2), a second circuit structure (3), an oil tank (4) and an electro-hydraulic reversing valve (5), the upper punch oil cylinder structure (1) being communicated with the oil tank (4) through the first circuit structure (2) and the second circuit structure (3), characterized in that: The upper top bolt oil cylinder structure (1) comprises a cross rod (101), a support rod (102), a piston (103), a sub-cylinder (104), a base (105), a vertical rod (106), a weight (107), a female cylinder (108) and a box (108), the base (105) is provided in two, and the two bases (105) are symmetrically installed on the two sides of the bottom of the box (109), the female cylinder (108) is arranged on the upper side of the base (105), the sub-cylinder (104) is arranged at the center of the female cylinder (108), the support rod (102) is hollow, the sub-cylinder (104) passes through the inside of the support rod (102), the piston (103) is fixedly connected with the tail end of the support rod (102), the piston (103) is slidably connected with the sub-cylinder (104), the cross rod (101) is arranged on the upper end of the support rod (102), the vertical rod (106) is fixedly connected with the cross rod (101), and the weight (107) is connected with the tail end of the vertical rod (106). The first circuit structure (2) is provided with a first pipeline (201) and a second pipeline (202), the electro-hydraulic reversing valve (5) is arranged on the second pipeline (201) and the second pipeline (202), the first pipeline (201) is connected with the sub-cylinder (104) at the beginning, and the first pipeline (201) passes through the base (105) and is connected with the sub-cylinder (104), the first pipeline (201) is provided with a first check valve (206), the lower pipeline is connected with the electro-hydraulic reversing valve (5), the pipeline is divided into two after passing through the electro-hydraulic reversing valve (5) and is connected with a second check valve (208) and a third check valve (209) respectively, the second check valve (208) is connected with a low-pressure pump (210) through a pipeline below, the third check valve (209) is connected with a high-pressure pump (212) and a first normally open electromagnetic overflow valve (207) through a pipeline below, the high-pressure pump (212) is provided with a servo motor (211) above, the pipeline branch between the second check valve (208) and the low-pressure pump (210) is connected with a third pipeline (203), the pipeline branch is provided with a second normally open electromagnetic overflow valve (213), the first normally open electromagnetic overflow valve (207) and the oil tank (4) are connected through a pipeline, and the low-pressure pump (210) and the high-pressure pump (212) are connected with the oil tank (4) below after the tail pipelines are combined; The second circuit structure (3) is connected with the pipeline above the first check valve (206), the second circuit structure (3) is sequentially provided with a first electromagnetic cut-off valve (301), a second pressure sensor (302), a low-pressure accumulator (303), a second electromagnetic cut-off valve (304), a back pressure check valve (305) and an electromagnetic reversing valve (306), the tail pipeline of the electromagnetic reversing valve (306) is divided into two and connected with a first throttle valve (307) and a second throttle valve (308), and the tail end of the second circuit structure (3) is connected with the oil tank (4). The electro-hydraulic reversing valve (5) comprises a main valve body (501), a main valve core (502) and an electromagnetic coil (503), the main valve body (501) is communicated with a first left lower pipeline (504), a left upper pipeline (505), a right lower pipeline (506), a right upper pipeline (507) and a second left lower pipeline (508) below, the first left lower pipeline (504) is connected with the second left lower pipeline (508), the main valve core (502) is arranged in the main valve body (501) and is in sliding connection with the main valve body (501), and the electromagnetic coil (503) is fixedly connected with the left and right ends of the main valve core (502).

2. A hydraulic control device for an internal mixer according to claim 1, characterized in that: The second pipeline (202) is connected with the upper side of the mother cylinder (108) and communicated with the mother cylinder (108) at the beginning, the high-pressure accumulator (204) and the first pressure sensor (205) are connected on the second pipeline (202), the lower pipeline is connected with the third pipeline (203) and the electro-hydraulic reversing valve (5) respectively, the overflow valve (214) is arranged on the pipeline connected with the third pipeline (203), the second pipeline (202) is connected with the third pipeline (203) after penetrating the electro-hydraulic reversing valve (5), and the third pipeline (203) is connected with the bottom of the mother cylinder (108) at the beginning.

3. A hydraulic control device for an internal mixer according to claim 1, characterized in that: The method comprises the following steps: Step one: the rotation speed of the control servo motor (211) is controlled to control the horizontal rod (101) in the internal mixer upper jack cylinder structure (1) to drive the weight (107) to rise fast or slowly; Step two: the control servo motor (211) is controlled to be at an appropriate rotation speed and the opening of the second throttle valve (308) is controlled to be large to control the weight (107) in the internal mixer upper jack cylinder structure (1) to descend fast; Step three: the control servo motor (211) is controlled to be at an appropriate rotation speed and the opening of the second throttle valve (308) is controlled to be small to control the weight (107) in the internal mixer upper jack cylinder structure (1) to descend slowly; Step four: according to the above steps one to three, the rotation speed of the control servo motor (211) and the opening of the second circuit structure (3) are controlled to control the horizontal rod (101) in the internal mixer upper jack cylinder structure (1) to rise or descend fast or slowly, so that the internal mixer is controlled to carry out rubber mixing or plastic mixing, and the control unit is controlled to control the actual pressure to control the action force of the weight on the rubber or plastic to be stable.

4. A hydraulic control device for an internal mixer according to claim 1, wherein: The control unit is connected with the first pressure sensor (205) and the servo motor (211).

Images