A tire blank reverse packaging molding method and system based on pneumatic servo control

Abstract

The invention discloses a tire embryo reverse packaging molding method and system based on pneumatic servo control. During the reverse packaging process, by monitoring the displacement variables of push plates on both sides within a unit acquisition time, the air supply pressure change of the air source on both sides is realized synchronously and dynamically, so as to realize the synchronous movement of the push plates on both sides. The system comprises a first servo proportional valve for adjusting the air supply pressure of the R-drum push plate air channel, a second servo proportional valve for adjusting the air supply pressure of the L-drum push plate air channel, an R-side distance measuring sensor for monitoring the displacement change of the R-drum push plate, an L-side distance measuring sensor for monitoring the displacement change of the L-drum push plate, and a single-chip microcomputer connected to each servo proportional valve and each distance measuring sensor. The method and system effectively overcome the asynchronous reverse packaging problem of the R-side and L-side and the obvious non-uniform change of materials in the existing reverse packaging molding process, so that the materials on both sides of the reverse packaging molding tire embryo are evenly distributed and symmetrical, the axial force defect of the tire formed by the tire embryo is greatly reduced, and the tire production quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tire manufacturing, and in particular to a tire blank reverse packaging molding method and system based on pneumatic servo control. Background Art

[0002] In the process of making rubber tire blanks, the existing forming drum needs to reverse the rubber material to form a shape, and this process generally takes several seconds to complete; Figure 1 The R-side drum 3 and the L-side drum 8 located on the left and right sides of the forming drum are driven by the R-drum pneumatic push plate 5 and the L-drum pneumatic push plate 10 to move toward each other and complete the turn-around.

[0003] Then, during the reverse packing process, the air source inlets for driving the R-drum pneumatic push plate 5 and the L-drum pneumatic push plate 10 to move are both arranged on the chassis 1 close to the R-side drum 3, resulting in the L-drum push plate air channel 11 connected between the L-drum pneumatic push plate 10 and the air source inlet being much longer than the R-drum push plate air channel 6 connected between the R-drum pneumatic push plate 5 and the air source inlet. The difference in distance from the air source inlet will inevitably lead to the need to use different pneumatic flow rates to control the movement of the two pneumatic push plates. This process is currently performed manually by identifying the rate difference with the naked eye, and manually adjusting the size of the reverse packing pneumatic pressure on both sides, thereby adjusting the pneumatic flow rate. However, the adjustment is currently made once after being identified by the human eye, resulting in poor synchronization of the reverse packing on both sides, making it impossible to effectively control such deformation of the tire, and only a certain degree of synchronization can be achieved.

[0004] On the other hand, since the rubber material used for extrusion molding to make tire embryos is a plastic material, it has the characteristic of partial uniformity. Therefore, from a process point of view, if the synchronization of the left and right sides during the wrapping process is poor, the final non-uniformity of the material will inevitably increase, making it impossible for the embryo to maintain the proper symmetry difference, which will lead to axial force defects on the tire side and affect the quality.

[0005] Based on this, it is necessary to further improve the current tire blank turn-up molding method to overcome the problems existing in the above-mentioned turn-up molding process, improve the symmetry of the tire blank shape, and thus improve the quality of the tire. Summary of the invention

[0006] The object of the present invention is to provide a tire blank reverse packaging molding method based on pneumatic servo control to solve the above technical problems.

[0007] Another object of the present invention is to provide a pneumatic servo control system for realizing the above-mentioned tire blank turn-up molding method based on pneumatic servo control.

[0008] To this end, the technical solution of the present invention is as follows:

[0009] A tire blank reverse packaging molding method based on pneumatic servo control, during the reverse packaging process, the air supply pressure of the R drum push plate air channel and the L drum push plate air channel is controlled synchronously and dynamically by the air source, so as to realize the synchronous movement of the R drum push plate and the L drum push plate;

[0010] Among them, the steps for controlling the air supply pressure in any push plate airway are:

[0011] S1, based on the length of the push plate airway, set the initial air supply pressure P i , so that the air source provides air supply pressure to the push plate airway P i , push the push plate to move;

[0012] S2, based on the set displacement variable acquisition cycle △ T , collect the displacement variable △S of the push plate, and calculate the average speed of the push plate under the current displacement variable △S V ;

[0013] S3, the average rate obtained in step S2 V and V ideal For comparison:

[0014] when V > V ideal ×(1+5%), then adjust the gas supply pressure to P = P i -a%× P i ,

[0015] when V < V ideal ×(1-5%), then adjust the gas supply pressure to P = P i + a%× P i ,

[0016] when V ideal ×(1-5%)≤ V ≤ V ideal ×(1+5%), then the gas supply pressure P = P i ,

[0017] In the formula, i for R or L , V idealThe ideal moving speed of the R drum push plate and the L drum push plate;

[0018] S4. Set the air supply pressure provided by the air source to the push plate airway to P , so that the push plate at the new air supply pressure P Displacement occurs under the action;

[0019] S5. Repeat the above steps S1 to S4 until the accumulated displacement variable ∑△S of the push plate reaches the moving distance S for the push plate to complete the reverse package.

[0020] Further, in step 2, the initial air supply pressure of the R drum push plate airway is 0.2Mpa~0.25Mpa, and the initial air supply pressure of the L drum push plate airway is 0.2Mpa~0.25Mpa; the ideal moving speed of the R drum push plate and the L drum push plate is V ideal It is 0.1m / s~0.12m / s.

[0021] Further, in step 3, the displacement variable acquisition period △ T Set to 0.02s~0.025s.

[0022] Further, in step 3, a% is 4% to 5%.

[0023] A pneumatic servo control system for tire blank reverse packaging, comprising:

[0024] A first servo proportional valve is arranged at the connection end of the R drum push plate air passage and the air source, so as to adjust the air supply pressure of the air source to the R drum push plate air passage through the flow rate of the first servo proportional valve;

[0025] A second servo proportional valve is provided at the connection end of the L-drum push plate air passage and the air source, so as to adjust the air supply pressure from the air source to the L-drum push plate air passage through the flow rate of the second servo proportional valve;

[0026] The R side distance sensor is used to monitor the displacement change of the R drum push plate on the main shaft;

[0027] The L-side distance sensor is used to monitor the displacement change of the L-drum push plate on the main shaft;

[0028] The single chip microcomputer is respectively connected with the first servo proportional valve, the second servo proportional valve, the R side distance sensor, and the L side distance sensor, and executes the above tire blank reverse packaging molding method based on pneumatic servo control.

[0029] Compared with the existing technology, the tire embryo turn-up molding method and system based on pneumatic servo control effectively overcomes the asynchronous turn-up problems of the R side and the L side and the obvious change of material non-uniformity in the existing turn-up molding process, and realizes uniform material distribution and good symmetry on both sides of the turn-up molding tire embryo, greatly reduces the axial force defects of the tire formed based on the tire embryo, and further improves the production quality of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a tire blank reverse packaging molding method based on pneumatic servo control of the present invention;

[0031] Figure 2 The displacement sampling result diagram of the R drum push plate and the L drum push plate from the initial 0 position over time, when the air pressure on both sides of the reverse package is manually adjusted by the human naked eye to identify the rate difference;

[0032] Figure 3 A sampling result diagram of the displacement of the R drum push plate and the L drum push plate from the initial 0 position over time when the pneumatic servo control-based tire blank turn-up molding method of the present invention is used to adjust the double-sided turn-up pneumatic pressure;

[0033] Figure 4 The diagram is a radial force test result diagram of tires formed by 20 tire blanks respectively formed by the current manual adjustment method and the adjustment method of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0035] In this embodiment, the specific implementation process of the tire blank reverse packaging molding method based on pneumatic servo control is described as follows.

[0036] Step 1: See Figure 1The existing tire blank reverse packaging molding device includes a chassis 1 and a main shaft 2; an air source is arranged in the chassis 1; an R-drum side drum 3 and an L-drum side drum 8 are installed on the outer side of the main shaft 2; an R-drum push plate air channel 6 and an L-drum push plate air channel 11 are arranged on the inner side of the main shaft 2; one end of the main shaft 2 is inserted into the chassis 1, so that one end of the R-drum push plate air channel 6 is connected to the air source through the R-drum valve, and one end of the L-drum push plate air channel 11 is connected to the air source through the L-drum valve; an R-drum reverse packaging rod 4 and an R-drum push plate 5 are arranged on the R-drum side drum 3, and the R-drum push plate 5 is connected to the other end of the R-drum push plate air channel 6, and the R-drum reverse packaging rod 4 is hingedly connected with the R-drum push plate 5, so that when the air source supplies air to the R-drum push plate 5 through the R-drum push plate air passage 6, the R-drum push plate 5 pushes the R-drum turn-up rod 4 to move toward the L side, thereby completing the R-side turn-up of the tire blank; an L-drum turn-up rod 9 and an L-drum push plate 10 are provided on the L-drum side drum 8, and the L-drum push plate 10 is connected with the other end of the L-drum push plate air passage 11, and the L-drum turn-up rod 9 is hingedly connected with the L-drum push plate 10, so that when the air source supplies air to the L-drum push plate 10 through the L-drum push plate air passage 11, the L-drum push plate 10 pushes the L-drum turn-up rod 9 to move toward the R side, thereby completing the L-side turn-up of the tire blank.

[0037] The structure of the existing tire blank turn-up molding device is improved, and a pneumatic servo control system for the tire blank turn-up molding is added to realize the tire blank turn-up molding method based on pneumatic servo control of the present invention; the specific improvement includes:

[0038] Step 1.1, a first servo proportional valve 7 is provided at the connection end between the R-drum push plate air passage 6 and the air source, so as to regulate the flow of the air source entering the R-drum push plate air passage 6 through the first servo proportional valve 7; a second servo proportional valve 12 is provided at the connection end between the L-drum push plate air passage 11 and the air source, so as to regulate the flow of the air source entering the L-drum push plate air passage 11 through the second servo proportional valve 12; further, by dynamically adjusting the flow of the air source entering the R-drum push plate air passage 6 and the L-drum push plate air passage 11 respectively, the air supply pressure in the two air passages is dynamically adjusted;

[0039] Step 1.2, add an R-side distance sensor 13 for monitoring the displacement change of the R-drum push plate 5, and add an L-side distance sensor 14 for monitoring the displacement change of the L-drum push plate 10; since the distance sensor 13 and the distance sensor 14 are used to monitor the displacement variables of the R-drum push plate 5 and the L-drum push plate 10, respectively, the two can be set at any position on the tire embryo turn-up molding device through a bracket, and can also be set on the adjacent side of the tire embryo turn-up molding device through a support frame alone;

[0040] Step 1.3, add a single chip microcomputer, which is respectively connected to the first servo proportional valve 7, the second servo proportional valve 12, the R side distance sensor 13, and the L side distance sensor 14, and processes the displacement variable signal received by the R side distance sensor 13 and the L side distance sensor 14 to determine the current movement state of the R drum push plate 5 and the L drum push plate 10, and then calculates the adjustment value of the air supply pressure according to the movement state of the two, and feeds back to the first servo proportional valve 7 and the second servo proportional valve 12, so as to quickly adjust the movement state of the two;

[0041] Step 2: According to the tire blank specifications and the length of the air ducts on both sides, set the initial air supply pressure of the R drum push plate air duct 6 respectively. P R , L initial air supply pressure of drum push plate airway 11 P L , the ideal moving speed of the R drum push plate 5 and the L drum push plate 10 V ideal , and the theoretical moving distance S of the R drum push plate 5 and the L drum push plate 10 to complete the reverse packing;

[0042] In this embodiment, the tire blank specification is 205 / 55R16, and the initial air supply pressure of the R drum push plate air passage 6 is P R Set to 0.2Mpa, the initial air supply pressure of the L drum push plate airway 11 P L Set to 0.22Mpa; Set the ideal moving speed of the R drum push plate 5 and the L drum push plate 10 V ideal 0.1 m / s, which is the optimal ideal time of the reverse operation determined based on the material properties of the tire blank raw material and the total displacement variable of the single-side push plate;

[0043] Step 3: During the entire movement of the R-drum push plate 5 and the L-drum push plate 10, the air supply pressure of the air source to the R-drum push plate airway 6 and the L-drum push plate airway 11 is synchronously and dynamically controlled. The specific steps are as follows:

[0044] 1) Dynamic control of R drum push plate 5:

[0045] Step 3.1: Initial air supply pressure based on R drum push plate airway 6 P R The first servo proportional valve 7 adjusts the air flow rate of the air source entering the R drum push plate airway 6, so that the R drum push plate 5 is initially at the air supply pressure P R Displacement occurs under the pressure of

[0046] Step 3.2: Based on the set displacement variable acquisition cycle △ T ,collection RDrum Push Plate 5 The displacement variable △ S R , and according to the formula: V R =△ S R / △ T , calculate the average velocity under the current displacement variable V R In this embodiment, the displacement variable acquisition cycle △ T Set to 0.025s.

[0047] Step 3.3: According to the average rate under the current displacement variable V R With ideal moving speed V ideal The following comparison is made:

[0048] when V R > V ideal ×(1+5%), the gas supply pressure should be adjusted P R for P’ = P R -5%× P R ;

[0049] when V R < V ideal ×(1-5%), the gas supply pressure should be adjusted P R for P’ = P R +5%× P R ;

[0050] when V ideal ×(1-5%)≤ V R ≤ V ideal ×(1+5%), then the gas supply pressure P’ = P R ,

[0051] Step 3.4: Set the new gas supply pressure P’ Update airway supply pressure P R, and sent to the first servo proportional valve 7, so that the first servo proportional valve 7 adjusts the air flow rate of the air source entering the R drum push plate airway 6, so that the R drum push plate 5 is at the new air supply pressure P R (Right now P’ ) under the pressure of displacement;

[0052] Step 3.5, repeat the above steps 3.2 to 3.4 until the cumulative displacement variable ∑△S of the R-drum push plate 5 reaches the theoretical moving distance S of the R-drum push plate 5;

[0053] 2) While performing the above step 1), dynamically control the L drum push plate 10:

[0054] Step 3.6: Initial air supply pressure based on L-drum push plate airway 11 P L The second servo proportional valve 12 adjusts the air flow rate of the air source entering the L drum push plate air channel 11, so that the L drum push plate 10 is initially at the air supply pressure P L Displacement occurs under the pressure of

[0055] Step 3.7: Based on the set displacement variable acquisition cycle △ T , collect the displacement variable △ of the L drum push plate 10 S L , and according to the formula: V L =△ S L / △ T , calculate the average velocity under the current displacement variable V L In this embodiment, the displacement variable acquisition cycle △ T Set to 0.025s.

[0056] Step 3.8: According to the average rate under the current displacement variable V L With ideal moving speed V ideal The following comparison is made:

[0057] when V L > V ideal ×(1+5%), the gas supply pressure should be adjusted P L for P” = P L -5%× P L ;

[0058] whenV L < V ideal ×(1-5%), the gas supply pressure should be adjusted P L for P” = P L +5%× P L ;

[0059] when V ideal ×(1-5%)≤ V L ≤ V ideal ×(1+5%), then the gas supply pressure P” = P L ,

[0060] Step 3.9: Set the new gas supply pressure P” Update airway supply pressure P L , and sent to the second servo proportional valve 12, so that the second servo proportional valve 12 adjusts the air flow rate of the air source entering the L drum push plate airway 11, so that the L drum push plate 10 is at the new air supply pressure P L (Right now P” ) displacement under the pressure of

[0061] Step 3.10: Repeat the above steps 3.7 to 3.9 until the cumulative displacement variable ∑△S of the L-drum push plate 10 reaches the theoretical moving distance S of the L-drum push plate 10.

[0062] In the process of the above step S3, the R-side distance sensor 13 and the L-side distance sensor 14 respectively monitor the displacement changes of the R-drum push plate 5 and the L-drum push plate 10 in real time in each acquisition cycle to determine whether the displacement rates of the two on the main shaft 2 meet the theoretical value, thereby adjusting the air supply pressure in the airway according to the average rate in the current acquisition cycle; specifically, the air supply pressure is adjusted by respectively adjusting the air intake of the first servo proportional valve 7 arranged between the air source and the R-drum push plate airway 6, and the second servo proportional valve 12 arranged between the air source and the L-drum push plate airway 10; In the above feedback adjustment process, the distance measuring sensor provides the displacement variable to the single-chip microcomputer in real time. After the single-chip microcomputer calculation, the current suitable air supply pressure is obtained and fed back to the servo proportional valve. The servo proportional valve receives the air supply pressure adjustment signal and quickly adjusts its own flow rate to achieve the adjustment of the air supply pressure in the push plate airway, thereby affecting the displacement change of the push plate, thereby establishing a time position control loop. This process is regulated in milliseconds, so that the influence of the difference in the double-sided backpacking is further reduced, and the shape of the tire blank maintains the due symmetry to a certain extent, which greatly improves the backpacking quality of the forming machine.

[0063] In order to further demonstrate the beneficial effects of the method of the present invention over the current traditional methods, tire blanks with the same specifications are made based on the same tire blank raw materials for reverse packaging operations. During the reverse packaging process, the displacement of the R drum push plate and the L drum push plate from the initial 0 position over time is sampled during the implementation of the two methods to analyze the difference between the two methods in the reverse packaging process.

[0064] like Figure 2 Shown is a graph showing the displacement sampling results of the R-drum push plate and the L-drum push plate from the initial 0 position over time, with the rate difference currently being manually adjusted by the naked eye to identify the pneumatic pressure on both sides; in addition, the figure also plots the L-side average trend line linear and the R-side average trend line based on the displacement sampling points of the R-drum push plate and the L-drum push plate from the initial 0 position over time.

[0065] See also Figure 2Based on the average trend line analysis of the L side and the R side, the sampling points on the L side and the R side in the range of sampling points 3 to 16 have large jitters up and down relative to the average trend line, which is related to the asynchrony of the R side reverse package and the L side reverse package; due to the large asynchrony of the push plates on both sides during the reverse package process, there are position errors between the sampling points in the figure, and there are also large differences in the reverse package arrival time on both sides; and the severity of this phenomenon generally increases with the frequency of user switching specifications, which will not only affect the subsequent tire manufacturing process based on the embryo, but also affect the overall quality of the tire. On the other hand, from the perspective of process, the rubber film used to make the embryo is a plastic material. During the molding process, the material has a large fluidity, and when making the embryo, the reverse molding process is carried out on the superimposed multiple layers of rubber films, which causes the material in the embryo molding process to produce non-uniform changes, that is, the quality of the two sides of the embryo is non-uniform; based on this, the existence of the asynchrony of the aforementioned R side reverse package and L side reverse package process will inevitably increase the non-uniform changes of the material; these two problems will eventually manifest as Figure 2 The large jitter phenomenon of the sampling points on the R side and the L side makes the symmetry of the two sides of the molded tire blank poor; in addition, compared with the average trend line of the L side and the average trend line of the R side, the R side is closer to the proportional valve and has a shorter air path, so its air supply is sufficient, and it has greater volatility. Its quality fluctuates more violently than that of the L side, making the material more biased towards the R side, which ultimately manifests as a tire side axial force defect and reduced tire quality for the finished tire.

[0066] like Figure 3 Shown is a graph showing the displacement sampling results of the R-drum push plate and the L-drum push plate from the initial 0 position over time when the double-sided turn-up pneumatic pressure is adjusted by the tire blank turn-up molding method based on pneumatic servo control of the present invention; in addition, based on the displacement sampling points of the R-drum push plate and the L-drum push plate from the initial 0 position over time, an L-side average trend line and an R-side average trend line are also drawn in the graph.

[0067] from Figure 3 It can be seen that the reverse operation is performed using the control method of the present invention, which realizes the synchronization of the L side and the R side at the millisecond level during the reverse operation, and greatly reduces the asynchronism in the movement of the push plates on both sides; from the perspective of process, the solution to the aforementioned asynchrony problem realizes the synchronous movement of the push plates on both sides, so that the aforementioned sampling point jitter problem disappears, and the sampling points on both sides fall on the average trend lines on both sides respectively, and the average trend line of the L side and the average trend line of the R side are also close to coincide, which further proves the synchronization of the movement of the push plates on both sides, and can thereby avoid the non-uniform changes of the material during the tire blank molding process, so that the materials on both sides of the tire blank are uniform and symmetrical, thereby overcoming the axial force defect of the tire.

[0068] like Figure 4Shown are the results of radial force tests on tires formed from 20 embryos formed by the current manual adjustment method and the adjustment method of the present invention; in the figure, the blue sampling points are the results of axial force tests on 20 tires formed from embryos made by the existing turn-around method, and an average trend line is drawn based on the blue sampling points; the red sampling points are the results of axial force tests on 20 tires formed from embryos made by the turn-around method of the present invention, and an average trend line is drawn based on the red sampling points; in this test, except for the turn-around control method, the other operating conditions of the two tests are the same.

[0069] from Figure 4 It can be seen from the figure that, compared with the existing control method, the axial force of the tire is significantly reduced after the tire is formed by the tire blank obtained by the control method of the present invention, which proves that the material uniformity and symmetry of the tire blank formed by the method of the present invention are better; the smaller tire axial force can make the tire produce smaller disturbance force in high-speed rotation mode, ensure the safety of the tire when in use, especially to obtain better steering force when turning; in addition, it can be clearly seen from the figure that the blue sampling point shakes violently up and down relative to its average trend line, which means that the stability of the axial force control of the tire blank by the existing method is poor, while the degree of shaking of the red sampling point up and down relative to its average trend line is significantly reduced, that is, the stability of the axial force control of the tire blank by the method of the present invention is good; that is, the tire blank formed by the control method of the present invention has the dual advantages of small axial force of the tire and stable quality of the tire blank.

[0070] In summary, the turn-up molding method and system of the present invention effectively overcome the asynchronous turn-up problems of the R-side and L-side and the obvious change in material non-uniformity in the existing turn-up molding process, and achieve uniform material distribution and good symmetry on both sides of the turn-up molding tire embryo, greatly reduce the axial force defects of the tire formed based on the tire embryo, and further improve the production quality of the tire.

Claims

1. A tire blank reverse packaging molding method based on pneumatic servo control, characterized in that: During the reverse packing process, the air supply pressure of the R drum push plate airway and the L drum push plate airway is controlled synchronously and dynamically by the air source, so as to realize the synchronous movement of the R drum push plate and the L drum push plate; Among them, the steps for controlling the air supply pressure in any push plate airway are: S1, based on the length of the push plate airway, set the initial air supply pressure P i , so that the air source provides air supply pressure to the push plate airway P i , push the push plate to move; S2, based on the set displacement variable acquisition cycle △ T , collect the displacement variable △S of the push plate, and calculate the average speed of the push plate under the current displacement variable △S V ; S3, the average rate obtained in step S2 V and V ideal For comparison: when V > V ideal ×(1+5%), then adjust the gas supply pressure to P = P i -a%× P i , when V < V ideal ×(1-5%), then adjust the gas supply pressure to P = P i + a%× P i , when V ideal ×(1-5%)≤ V ≤ V ideal ×(1+5%), then the gas supply pressure P = P i , In the formula, i for R or L , V ideal The ideal moving speed of the R drum push plate and the L drum push plate; S4. Set the air supply pressure provided by the air source to the push plate airway to P , so that the push plate at the new air supply pressure P Displacement occurs under the action; S5. Repeat the above steps S1 to S4 until the accumulated displacement variable ∑△S of the push plate reaches the moving distance S for the push plate to complete the reverse package.

2. The tire blank turn-up molding method based on pneumatic servo control according to claim 1, characterized in that: In step 2, the initial air supply pressure of the R drum push plate airway is 0.2Mpa~0.25Mpa, and the initial air supply pressure of the L drum push plate airway is 0.2Mpa~0.25Mpa; the ideal moving speed of the R drum push plate and the L drum push plate is V ideal It is 0.1m / s~0.12m / s.

3. The tire blank turn-up molding method based on pneumatic servo control according to claim 1, characterized in that: In step 3, the displacement variable acquisition period △ T Set to 0.02s~0.025s.

4. The tire blank turn-up molding method based on pneumatic servo control according to claim 1, characterized in that: In step 3, a% is 4%~5%.

5. A pneumatic servo control system for tire blank turn-up molding, characterized in that: include: A first servo proportional valve is arranged at the connection end of the R drum push plate air passage and the air source, so as to adjust the air supply pressure of the air source to the R drum push plate air passage through the flow rate of the first servo proportional valve; A second servo proportional valve is provided at the connection end of the L-drum push plate air passage and the air source, so as to adjust the air supply pressure from the air source to the L-drum push plate air passage through the flow rate of the second servo proportional valve; The R side distance sensor is used to monitor the displacement change of the R drum push plate on the main shaft; The L-side distance sensor is used to monitor the displacement change of the L-drum push plate on the main shaft; The R-side distance sensor and the L-side distance sensor respectively monitor the displacement changes of the R-drum push disk and the L-drum push disk in each acquisition cycle in real time to determine whether the displacement rates of the R-drum push disk and the L-drum push disk on the main shaft meet the theoretical values, thereby adjusting the air supply pressure in the airway according to the average rate in the current acquisition cycle; A single chip microcomputer is respectively connected to the first servo proportional valve, the second servo proportional valve, the R side distance measuring sensor, and the L side distance measuring sensor, and executes the method as claimed in claim 1.

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