Sheet metal positioning cylinder and pneumatic positioning system

Abstract

The utility model discloses a sheet metal positioning cylinder. The sheet metal positioning cylinder comprises a cylinder body, a first mechanism, a second mechanism and a compression spring. The first mechanism comprises a taper pin pull head, a piston rod and a piston. The second mechanism comprises an inner taper face spring piece and a guide sleeve. The compression spring abuts against the lower end face of the guide sleeve. The taper pin pull head extends upward with the movement of the piston rod to be inserted into the positioning hole of the sheet metal. With the retraction of the piston rod, the inner taper face spring piece is pushed to expand radially and move downward. The inner taper face spring piece extends with the taper pin pull head to be inserted into the positioning hole of the sheet metal. With the retraction of the taper pin pull head, the inner taper face spring piece expands radially to grab the sheet metal and move downward to tighten the sheet metal for positioning. The utility model has the advantages of being suitable for smaller-diameter positioning holes, reducing production cost, eliminating mechanical interference and enhancing positioning stability.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic technology, and in particular to a sheet metal positioning cylinder and a pneumatic positioning system. Background Technology

[0002] Car doors are primarily manufactured through multiple processes including sheet metal cutting, stamping, welding, and assembly. During door assembly, several process holes must be installed. Among these, positioning holes, which work in conjunction with positioning devices to restrict the freedom of the sheet metal workpiece, ensure the door's accurate positioning during certain processes. Currently, positioning the car door using these positioning holes typically employs a hook-type pneumatic pin cylinder as the positioning tool. This involves extending a hook from the cylinder's tip into the positioning hole and applying tension to the sheet metal to achieve positioning.

[0003] However, when the diameter of the positioning hole is smaller than a certain range, this hook-type positioning tool will cause spatial interference to the positioning hole mechanically during use: on the one hand, the hook cannot retract into the pin cap, and on the other hand, the hook has a destructive effect on the flanged positioning hole, requiring additional groove modification before it can be used. Utility Model Content

[0004] In view of the above problems, the purpose of this utility model is to provide a sheet metal positioning cylinder and a pneumatic positioning system.

[0005] In a first aspect, this utility model embodiment provides a sheet metal positioning cylinder, comprising:

[0006] Cylinder body, first mechanism, second mechanism, and compression spring;

[0007] The first mechanism and the second mechanism are disposed in a cavity formed inside the cylinder body; the first mechanism is movably sleeved on the inside of the second mechanism; the second mechanism is movably sleeved on the inner wall of the cavity;

[0008] The first mechanism includes: a tapered pin pull head, a piston rod, and a piston, which are fixedly connected from top to bottom;

[0009] The second mechanism includes: an inner conical spring and a guide sleeve fixedly connected from top to bottom;

[0010] The compression spring is disposed in the cavity and abuts against the lower end face of the guide sleeve;

[0011] The tapered pin pull head extends upward as the piston rod moves to insert into the positioning hole of the sheet metal; and as the piston rod retracts downward, it pushes the inner tapered spring, causing the inner tapered spring to expand radially and move downward.

[0012] The inner conical spring extends along with the tapered pin pull head to insert into the positioning hole of the sheet metal; and expands radially as the tapered pin pull head retracts to grip the sheet metal and move downward to tighten the sheet metal for positioning.

[0013] In one embodiment, it further includes: a limiting block;

[0014] The limiting block is circumferentially disposed on the outer wall of the piston rod;

[0015] The limiting block is located within the limited space formed by the piston rod, the inner conical spring, and the guide sleeve.

[0016] In one embodiment, it further includes: a sensing air passage disposed in the cylinder body;

[0017] The inlet of the sensing air passage is located on the side of the cylinder body; the outlet of the sensing air passage is located on the upper surface of the cylinder body.

[0018] In one embodiment, the air inlet of the sensing air path is used to connect to an external first air source.

[0019] In one embodiment, it further includes: a pressure switch disposed on the side of the cylinder body;

[0020] The pressure switch is connected to the sensing air circuit and is used to detect the exhaust pressure in the sensing air circuit. When the exhaust pressure reaches the preset threshold pressure of the pressure switch, the positioning hole positioning signal is output.

[0021] In one embodiment, the preset threshold pressure of the pressure switch is equivalent to the gas source pressure of the first gas source.

[0022] In one embodiment, the chamber includes: a first chamber and a second chamber that are interconnected;

[0023] The first chamber is located above the second chamber;

[0024] The piston rod passes through the first chamber; the piston is disposed in the second chamber.

[0025] In one embodiment, the second chamber is used to connect to an external second air source;

[0026] The second air source is used to supply air to the second chamber to drive the piston and drive the tapered pin pull head to move axially.

[0027] In one embodiment, the cylinder body includes: an upper end cover, a lower end cover, and a cylinder barrel.

[0028] Secondly, this utility model provides a pneumatic positioning system, including a plurality of the aforementioned sheet metal positioning cylinders.

[0029] The beneficial effects of the above-mentioned technical solutions provided by the embodiments of this utility model include at least the following:

[0030] This utility model provides a sheet metal positioning cylinder. Through the coordinated design of a tapered pin pull head and an inner tapered spring, the inner tapered spring radially grips the sheet metal during the retraction of the tapered pin pull head and pulls the sheet metal downward to achieve positioning of the positioning hole. For flanged positioning holes, traditional hook-type pneumatic pin cylinders require additional grooves before application. This utility model cylinder can be used directly for flanged positioning holes without grooves, avoiding spatial interference with the flanged positioning holes and preventing edge deformation or scratches, thus improving the assembly yield of the door. The diameter of the tapered pin pull head can be adapted to smaller process holes, avoiding the reduction in sheet metal strength caused by enlarging the size of the process holes, while reducing material waste and processing costs. Alternatively, existing small-diameter functional holes in the door can be directly used as temporary positioning holes without the need for additional processing of dedicated positioning holes, simplifying the process and reducing equipment investment.

[0031] Furthermore, by using a pressure switch to monitor the exhaust pressure in the sensing air circuit in real time, and by combining this with a magnetic switch to monitor the position of the limit block or piston, automatic feedback of the positioning status (positioning completed / incomplete) of the positioning hole can be achieved, ensuring the stability of continuous operation of the production line and reducing the risk of manual intervention and downtime.

[0032] Furthermore, by setting a limiting block on the piston rod, the inner conical spring can be prevented from being damaged or fatigued due to continuous radial expansion during the positioning process before the positioning hole is fully positioned, thus extending the service life of the system.

[0033] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0034] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is an overall appearance view of the sheet metal positioning cylinder in the embodiment of this utility model;

[0037] Figure 2This is a schematic diagram of the sheet metal positioning cylinder positioning sheet metal in an embodiment of this utility model;

[0038] Figure 3 This is a schematic diagram of the sheet metal positioning cylinder structure in an embodiment of this utility model.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Tapered pin pull head; 2. Piston rod; 3. Piston; 4. Sheet metal; 5. Inner conical surface spring; 6. Guide sleeve; 7. Compression spring; 8. Limit block; 9. Pressure switch; 10. First magnetic switch; 11. Second magnetic switch; 12. Upper end cover; 13. Lower end cover; 14. Cylinder barrel; 15. Sensing air inlet; 16. Sensing air outlet; 17. Cylinder body. Detailed Implementation

[0041] Definitions:

[0042] Process holes: For example, in the manufacturing process of automobiles, holes are made to ensure the achievement of certain processes, such as positioning and clamping, to meet the needs of the production process.

[0043] Functional holes: such as mounting holes for automotive parts, fastening holes, or wiring holes for automotive wiring.

[0044] Initial state: This is short for the initial state of the system, which means that the piston in the positioning cylinder of this utility model embodiment is at the top of the second chamber, and the tapered pin pull head and the inner tapered surface spring are at the highest point in the axial direction.

[0045] Normal operation: refers to a series of complex actions during the positioning process of the positioning cylinder in this embodiment of the utility model to position the reserved positioning hole of the sheet metal.

[0046] Abnormal action: refers to the failure of the positioning cylinder in this embodiment of the utility model to perform the combined action of positioning the positioning hole.

[0047] Overview of embodiments of this utility model:

[0048] In the process of locating positioning holes in car doors, existing technologies mainly use hook-type positioning tools. The inventors discovered that this often results in interference between the hook and the flanged positioning hole, requiring modifications such as adding grooves to the flanged positioning hole. To address these issues, the inventors designed a novel structural form different from traditional tools through continuous experimentation and improvement. This new structure utilizes the frictional force generated by the orderly movement of mechanical mechanisms to resolve the interference problem in positioning the flanged hole. Furthermore, the inventors found that the diameter of the hook in the hook-type positioning tool must meet design requirements, typically a minimum design value of Φ12mm to Φ16mm. If the hook diameter is smaller than the design value, it may lead to breakage, deformation, or other hazards. Since car doors are mass-produced on assembly lines, hook malfunction would inevitably affect production efficiency and progress. Increasing the diameter of the process hole to accommodate the hook specifications would not only increase costs but also reduce the strength of the car door. The positioning cylinder provided in this embodiment of the invention, due to its unique structure, can be adapted to smaller process holes by reducing the size of the tapered pin pull head, for example, the diameter can be reduced to less than Φ10mm; or existing smaller functional holes can be temporarily used as process holes without the need to process additional small positioning holes. The positioning cylinder of this invention can improve the efficiency of door assembly, reduce equipment investment, and ensure the strength of the door.

[0049] This embodiment provides a sheet metal positioning cylinder and a pneumatic positioning system. Although exemplary embodiments of this disclosure are shown in the accompanying drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0050] In a first aspect, this utility model embodiment provides a sheet metal positioning cylinder, referring to... Figure 1 , Figure 2 and Figure 3 ,include:

[0051] Cylinder body 17, first mechanism, second mechanism and compression spring 7;

[0052] The first mechanism and the second mechanism are disposed in a cavity formed inside the cylinder body 17; the first mechanism is movably sleeved on the inside of the second mechanism; the second mechanism is movably sleeved on the inner wall of the cavity;

[0053] The first mechanism includes: a tapered pin pull head 1, a piston rod 2, and a piston 3, which are fixedly connected from top to bottom;

[0054] The second mechanism includes: an inner conical spring 5 and a guide sleeve 6 fixedly connected from top to bottom;

[0055] The compression spring 7 is disposed in the cavity and abuts against the lower end face of the guide sleeve 6;

[0056] The tapered pin pull head 1 extends upward as the piston rod 2 moves to insert into the positioning hole of the sheet metal 4; and as the piston rod 2 retracts downward, it pushes the inner tapered spring 5, causing the inner tapered spring 5 to expand radially and move downward.

[0057] The inner conical spring 5 extends out together with the conical pin pull head 1 to insert into the positioning hole, and expands radially as the conical pin pull head 1 retracts to grip the sheet metal 4 and move downward to tighten the sheet metal 4 for positioning.

[0058] The sheet metal positioning cylinder provided in this embodiment can be used in the positioning process of body positioning holes, for example, during the production of automobile doors. Addressing the shortcomings of existing positioning tools such as hook-type pneumatic pin cylinders, including large positioning hole diameters, easy interference, and low efficiency, the positioning cylinder of this invention utilizes the frictional force generated after the inner conical spring 5 grips the sheet metal 4, pulling the sheet metal 4 downwards to achieve spatial positioning (six degrees of freedom positioning in three directions: x-axis, y-axis, and z-axis). The positioning air hole of this invention can adapt to small-diameter positioning holes, reducing production costs, eliminating mechanical interference, and enhancing positioning stability. It is suitable for high-precision, mass production scenarios such as automobile door manufacturing.

[0059] In one embodiment, refer to Figure 1 The cylinder of this utility model further includes: a sensing air passage disposed in the cylinder body 17; a sensing air passage inlet 15 disposed on the side of the cylinder body 17; and a sensing air passage outlet 16 disposed on the upper end face of the cylinder body 17.

[0060] In one embodiment, refer to Figure 1 The inlet 15 of the sensing air path is used to connect to an external first air source. The outlet 16 of the sensing air path is connected to the outside atmosphere, and the first air source is used to supply air to the sensing air path.

[0061] In one embodiment, refer to Figures 1-3 A pressure switch 9 is installed on the side of the cylinder body 17. The pressure switch 9 is connected to the sensing air circuit and is used to detect the exhaust pressure in the sensing air circuit. When the exhaust pressure reaches a preset threshold pressure, the pressure switch 9 outputs a positioning signal for the positioning hole. Specifically, the pressure switch 9 is equipped with a pressure sensor that can sense changes in the air pressure in the sensing air circuit. The preset threshold pressure of the pressure switch 9 can be adjusted according to the actual situation on site.

[0062] In one embodiment, the preset threshold pressure of pressure switch 9 is equal to the air source pressure of the first air source, or the preset threshold pressure is set to be close to the air source pressure of the first air source. When the exhaust port 16 of the sensing air path is unobstructed and the air path is unobstructed, the exhaust pressure sensed by the air pressure sensor is almost the same as the external atmospheric pressure. During the process of the inner conical spring 5 gripping the sheet metal 4 and pulling it downward, no positioning signal is output at this time. Until the sheet metal 4 pulled downward is pressed against the upper end face of the cylinder body 17 and covers the exhaust port, the exhaust pressure in the sensing air path rises rapidly. When the exhaust pressure reaches the preset threshold pressure of pressure switch 9, pressure switch 9 outputs a positioning hole positioning signal.

[0063] In one embodiment, the chamber includes a first chamber and a second chamber that are interconnected; the first chamber is disposed above the second chamber; see reference. Figure 3 The piston rod 2 passes through the first chamber, while the piston 3 is located in the second chamber. Specifically, the axial movement range of the piston 3 in the first mechanism is limited by the space of the second chamber. The lower end of the piston rod 2 is connected to the piston 3, and the upper end is connected to the tapered pin pull head 1. A part of the piston rod 2 and the tapered pin pull head 1 are located in the first chamber. The second mechanism and the compression spring 7 are both located in the first chamber.

[0064] In one embodiment, refer to Figure 2 and Figure 3 The cylinder of this utility model also includes: a first magnetic switch 10; the first magnetic switch 10 is disposed on the side of the cylinder body 17 and is used to detect the position of the piston 3. When the piston 3 reaches the top of the second chamber, it outputs an initial state signal. Specifically, during the upward movement of the piston 3, it will drive the piston rod 2 and the tapered pin pull head 1 at the end of the piston rod 2 to extend upward together. When the piston 3 reaches the top of the second chamber, it reaches the limit state of the upward movement of the first mechanism, which is the specified system initial state. When the first magnetic switch 10 detects that the system is in the initial state at this time, it outputs an initial state signal, which, in combination with actual engineering, can be defined as the Home origin signal.

[0065] In one embodiment, refer to Figure 3 The cylinder of this utility model also includes a limiting block 8; the limiting block 8 is circumferentially disposed on the outer wall of the piston rod 2; the limiting block 8 is located within the limited space formed by the piston rod 2, the inner conical spring 5, and the guide sleeve 6. Specifically, the limiting block 8 is disposed below the inner conical spring 5, fixedly connected to the piston rod 2, and moves axially together with the piston rod 2.

[0066] In one embodiment, refer to Figure 2 and Figure 3The cylinder of this utility model also includes a second magnetic switch 11; the second magnetic switch 11 is disposed on the side of the cylinder body 17 and is used to detect the position of the piston 3. When the piston 3 reaches the bottom of the second chamber, it outputs a positioning hole positioning failure signal. Specifically, assuming that the tapered pin pull head 1 of the first mechanism fails to be inserted into the positioning hole reserved in the sheet metal 4, during the downward movement of the tapered pin pull head 1, although it will also push the inner tapered surface spring 5 to expand radially and move downward, the inner tapered surface spring 5 will not grab the sheet metal 4, and naturally will not tighten the sheet metal 4 to achieve positioning. At this time, the air passage exhaust port 16 of the sensing air passage is completely unobstructed because it is not blocked by the sheet metal 4, and the pressure switch 9 will not output a positioning hole positioning signal. In this case, the piston 3 continues to move downward, and the tapered pin pull head 1 moves downward relative to the inner tapered surface spring 5. When the limiting block 8 on the piston rod 2 hits the guide sleeve 6, under the action of the limiting block 8, the first mechanism will drive the second mechanism to move downward together. At this time, there is no relative movement between the tapered pin pull head 1 and the inner tapered surface spring 5. When piston 3 reaches the bottom of the second chamber, the second magnetic switch 11 outputs a positioning hole positioning failure signal. It is evident that in the event of positioning failure, due to the setting of the limit block 8, after the limit block 8 impacts the guide sleeve 6, the tapered pin pull head 1 can move downwards together with the inner tapered spring 5 without relative movement between them. This prevents the inner tapered spring 5 from being damaged by continuous radial expansion or fatigue damage, thereby increasing the system's service life. In reality, the probability of the sheet metal 4 positioning hole failing to achieve positioning in the workshop is relatively small (because of the layered inspection process, the probability of not drilling process holes is low). However, once this situation occurs, it indicates a potentially significant safety hazard in the assembly line production. If not detected in time, it could lead to huge economic losses. Manual inspection is impractical; the second magnetic switch 11 can quickly and in real-time send abnormal detection signals to technicians.

[0067] In one embodiment, the second chamber is used to connect to an external second air source; the second air source is used to supply air to the second chamber, pushing the piston 3 to drive the tapered pin pull head 1 to move axially. Specifically, refer to... Figure 3 When air is injected into the lower end face of piston 3, piston 3 moves axially upward, simultaneously causing piston rod 2 and tapered pin pull head 1 to move upward as well. When air is injected into the upper end face of piston 3, piston 3 moves axially downward, simultaneously causing piston rod 2 and tapered pin pull head 1 to move downward as well. It is evident that the second air source is the power source for the movement of both the first and second mechanisms.

[0068] In one embodiment, refer to Figure 3 The cylinder body 17 includes an upper end cover 12, a lower end cover 13, and a cylinder barrel 14. Specifically, the upper end cover 12 is fixedly connected to the upper end of the cylinder barrel 14, the lower end cover 13 is fixedly connected to the lower end of the cylinder barrel 14, and the induction air passage exhaust port 16 is provided on the upper end cover 12.

[0069] In one embodiment, the aforementioned initial state signal, positioning hole positioning signal, and positioning hole positioning failure signal can be displayed, for example, by illuminating an indicator light.

[0070] Reference Figures 1-3 In summary, during normal operation testing, the positioning cylinder provided by this utility model performs the following combined positioning action on the positioning hole:

[0071] Action 1: Piston 3 moves upward to the top of the second chamber, and the first magnetic switch 10 displays the initial state signal. The tapered pin pull head 1 is inserted into the positioning of the sheet metal 4, and the tapered pin pull head 1 and the inner tapered spring 5 are at their highest axial positions. At this time, the system returns to the initial state.

[0072] Action 2: The piston 3 drives the tapered pin pull head 1 to move downward. When the downward pulling force on the tapered spring 5 caused by the piston 3 is less than the upward preload of the compression spring 7, the inner tapered spring 5 remains stationary in the axial direction and expands radially. When the outer side of the inner tapered spring 5 contacts the inner wall of the positioning hole, the expansion stops, and the sheet metal 4 is gripped.

[0073] Action 3: After the inner conical spring 5 grips the sheet metal 4, the relative movement between the conical pin pull head 1 and the inner conical spring 5 stops. At this time, the piston 3 continues to move downward. When the downward pulling force caused by the piston 3 is greater than the upward preload of the compression spring 7, the sheet metal 4, the conical pin pull head 1, and the inner conical spring 5 move together towards the upper end cover 12 under the drive of the piston 3. When the sheet metal 4 presses against the upper surface of the upper end cover 12, it will block the exhaust port 16 of the sensing air circuit, causing the exhaust pressure in the sensing air circuit to rise, triggering the pressure switch 9 and displaying the positioning hole positioning signal.

[0074] During abnormal motion detection, the positioning process of the positioning cylinder provided by this utility model for positioning the positioning hole is summarized as follows:

[0075] Action 1: The system returns to the initial state. The first magnetic switch 10 displays the initial state signal, but the tapered pin pull head 1 fails to insert into the positioning hole reserved in the sheet metal 4.

[0076] Actions 2 and 3: The actions of the first and second mechanisms are the same as the aforementioned normal action detection process, but since positioning is impossible, the pressure switch 9 does not display the positioning hole positioning signal.

[0077] Action 4: Piston 3 continues to move downwards, and the tapered pin pull head 1 moves downwards relative to the inner tapered surface spring 5. When the limiting block 8 on piston rod 2 hits the guide sleeve 6, the limiting block 8 continues to move. Under the action of the limiting block 8, the first mechanism and the second mechanism move downwards together, and there is no longer any relative movement between the tapered pin pull head 1 and the inner tapered surface spring 5. When piston 3 reaches the bottom of the second chamber, the second magnetic switch 11 outputs a positioning hole positioning failure signal, realizing an abnormal action alarm.

[0078] This invention also provides a pneumatic positioning system, which includes a plurality of sheet metal positioning cylinders as described in the first aspect above.

[0079] Obviously, those skilled in the art can make various changes to this utility model without departing from its spirit and scope. Therefore, if these modifications fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications.

Claims

1. A sheet metal positioning cylinder, characterized in that, include: Cylinder body, first mechanism, second mechanism, and compression spring; The first and second mechanisms are disposed in the chamber formed inside the cylinder body; The first mechanism is movably fitted inside the second mechanism; the second mechanism is movably fitted inside the inner wall of the chamber; The first mechanism includes: a tapered pin pull head, a piston rod, and a piston, which are fixedly connected from top to bottom; The second mechanism includes: an inner conical spring and a guide sleeve fixedly connected from top to bottom; The compression spring is disposed in the cavity and abuts against the lower end face of the guide sleeve; The tapered pin pull head extends upward as the piston rod moves to insert into the positioning hole of the sheet metal; and as the piston rod retracts downward, it pushes the inner tapered spring, causing the inner tapered spring to expand radially and move downward. The inner conical spring extends along with the tapered pin pull head to insert into the positioning hole of the sheet metal; and expands radially as the tapered pin pull head retracts to grip the sheet metal and move downward to tighten the sheet metal for positioning.

2. The cylinder as described in claim 1, characterized in that, Also includes: Limit block; The limiting block is circumferentially disposed on the outer wall of the piston rod; The limiting block is located within the limited space formed by the piston rod, the inner conical spring, and the guide sleeve.

3. The cylinder as described in claim 2, characterized in that, Also includes: The sensing air passage is set in the cylinder body; The inlet of the sensing air passage is located on the side of the cylinder body; the outlet of the sensing air passage is located on the upper surface of the cylinder body.

4. The cylinder as described in claim 3, characterized in that, The air inlet of the sensing air circuit is used to connect to an external first air source.

5. The cylinder as described in claim 4, characterized in that, Also includes: A pressure switch is provided on the side of the cylinder body; The pressure switch is connected to the sensing air circuit and is used to detect the exhaust pressure in the sensing air circuit. When the exhaust pressure reaches the preset threshold pressure of the pressure switch, the positioning hole positioning signal is output.

6. The cylinder as described in claim 5, characterized in that, The preset threshold pressure of the pressure switch is equivalent to the gas source pressure of the first gas source.

7. The cylinder as described in claim 1, characterized in that, The chamber includes: a first chamber and a second chamber that are interconnected; The first chamber is located above the second chamber; The piston rod passes through the first chamber; the piston is disposed in the second chamber.

8. The cylinder as described in claim 7, characterized in that, The second chamber is used to connect to an external second air source; The second air source is used to supply air to the second chamber to drive the piston and drive the tapered pin pull head to move axially.

9. The cylinder according to any one of claims 1-8, characterized in that, The cylinder body includes: an upper end cover, a lower end cover, and a cylinder barrel.

10. A pneumatic positioning system, characterized in that, It includes a plurality of sheet metal positioning cylinders as described in any one of claims 1-9.

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