Oblique comb guide roller riveting method and riveting equipment

Abstract

The invention discloses an oblique comb guide roller riveting method and a riveting device thereof, which comprises the following steps: placing an aluminum plate base riveted with a blowing plate on a lower mold moving plate; the direction of the blowing plate forms an angle a with the moving trajectory line of the lower mold moving plate, and the angle a is 20 to 80 degrees; pushing the lower mold moving plate to move to an assembly position; a positioning device fixes the position of the lower mold moving plate; the positioning plate moves to the rear side of the blowing plate; the oblique comb plate gradually slides from the outer edge of the aluminum plate base to the center position along the angle a, so that the oblique comb plate is pressed against the positioning plate, and the oblique comb plate uses a combing groove to comb and straighten the blowing plate during the sliding process, so that the rivet protrusions on the blowing plate are all positioned at predetermined positions; a cover plate is covered on the blowing plate, and each rivet protrusion on the blowing plate can be aligned and matched with the rivet holes on the cover plate one by one, and the rivet protrusions on the blowing plate are riveted to realize the riveting of the cover plate on the blowing plate, which saves time and labor and has high work efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of riveting, and in particular to an oblique comb guide roller riveting method and a riveting device thereof. Background Art

[0002] In some application fields, the blown plate and the cover plate need to be riveted together. The traditional process is: the blown plate is pre-riveted on the aluminum plate base to form a heat dissipation module, and the heat dissipation module is placed on the fixture. Before the rolling riveting process, the blown plate on the aluminum plate base needs to be manually adjusted and straightened, and then the cover plate is covered so that the rivet bumps on the blown plate are inserted into the rivet holes of the cover plate, and then the rivet bumps are riveted to achieve the purpose of riveting.

[0003] However, the blowing plate is prone to shaking during the manual adjustment and alignment process, making it difficult to align the rivet protrusions on the blowing plate with the rivet holes on the cover plate. At the same time, when the blowing plate is covered with the cover plate, the blowing plate is prone to tilt and shift after the hands are loosened. At this time, the blowing plate needs to be adjusted and aligned again. Moreover, the number of blowing plates ranges from a few to dozens or hundreds, and multiple people are required to adjust and align them one by one, which is time-consuming and labor-intensive. In particular, the blowing plates are arranged at an inclined angle, and the narrow operating space makes it difficult to manually adjust and align them, making it difficult to ensure the quality of rolling rivets, and easily producing defective products. Summary of the invention

[0004] In view of the above-mentioned shortcomings, the object of the present invention is to provide an oblique comb guide roller riveting method which can facilitate the adjustment and straightening of the blown plate and facilitate riveting.

[0005] The present invention also aims to provide an oblique comb-guided roller riveting device.

[0006] To achieve the above object, the technical solution provided by the present invention is: an oblique comb guide roller riveting method, which comprises the following steps:

[0007] (1) placing an aluminum plate base riveted with a blown plate on a lower mold movable plate; wherein the direction of the blown plate forms an angle a with the moving trajectory of the lower mold movable plate;

[0008] (2) Push the lower mold moving plate to the assembly position;

[0009] (3) The positioning device fixes the position of the lower mold moving plate;

[0010] (4) The positioning plate is moved to the rear side of the blowing plate;

[0011] (5) The oblique combing plate gradually slides from the outer edge of the aluminum plate base to the center of the aluminum plate base along the included angle a, and the oblique combing plate is pressed against the positioning plate. During the sliding process, the oblique combing plate uses the combing groove on it to comb and straighten the blowing plate, so that the rivet protrusions on the blowing plate are all positioned at the predetermined positions;

[0012] (6) Put the cover plate on the inflation plate, and the rivet protrusions on each inflation plate can be aligned and matched with the rivet holes on the cover plate one by one;

[0013] (7) Riveting the rivet protrusions on the blown plate to achieve riveting of the cover plate on the blown plate to obtain a riveted product;

[0014] (8) The oblique comb plate returns to its initial position;

[0015] (9) The positioning plate returns to its initial position;

[0016] (10) The positioning device releases the lower mold moving plate;

[0017] (11) The lower die moving plate returns to its initial position and the riveted product is taken out;

[0018] (12) Repeat steps (1) to (11) to complete a new round of oblique comb-guided roller riveting process.

[0019] As a preferred solution of the present invention, a center guide plate extending along the moving trajectory of the lower mold moving plate is provided on the center line of the assembly position through a positioning seat, and a positioning recess matched with the positioning seat is provided on the lower mold moving plate. A center positioning inclined convex matched with the combing groove when the oblique combing plate slides to the center position of the aluminum plate base is provided on the side wall of the center guide plate. A side positioning inclined convex matched with the combing groove when the oblique combing plate slides to the center position of the aluminum plate base is provided on the positioning plate, and a sliding groove matched with the center guide plate is provided on the positioning plate. The lower mold moving plate is accurately positioned when it is moved to the assembly position by the positioning seat; the oblique combing plate is accurately positioned after combing and straightening by the center guide plate.

[0020] As a preferred solution of the present invention, the inflation plates are divided into two groups and symmetrically distributed on both sides of the center line of the aluminum plate base, and a central slot for the central guide plate to extend into is formed between the two groups of inflation plates.

[0021] A kind of oblique comb guide roller riveting equipment, which comprises a workbench, a lower mold moving plate, a positioning device, an oblique comb plate, a positioning plate, a propulsion device, a conveying device and a lifting device, wherein a center line guide rail is arranged on the workbench, the lower mold moving plate is movably arranged on the center line guide rail, the conveying device is arranged on the workbench, and can drive the lower mold moving plate to make a reciprocating motion on the center line guide rail, the side position of the workbench corresponding to the center line guide rail is provided with a side linear guide rail, the side linear guide rail and the center line guide rail form an included angle a, the oblique comb plate is movably arranged on the side linear guide rail, the propulsion device is arranged on the workbench, and can drive the oblique comb plate to make a reciprocating motion on the side linear guide rail; the positioning plate is arranged on the workbench through the lifting device at a position corresponding to the lower mold moving plate moving to the assembly position; the positioning device is arranged on the workbench corresponding to the position of the lower mold moving plate moving to the assembly position, and a positioning hole compatible with the positioning device can be provided on the lower mold moving plate.

[0022] As a preferred solution of the present invention, it also includes a positioning seat and a center guide plate. The positioning seat is set at the end position of the center line guide rail. One end of the center guide plate is fixed on the positioning seat, and the other end extends to the middle position of the positioning plate. The middle of the positioning plate is provided with a sliding groove that matches the center guide plate; the lower mold moving plate is provided with a positioning recess that matches the positioning seat. The addition of a center guide plate can position and fix the oblique combing plate after combing and straightening to avoid displacement, and cooperate with the lifting and lowering action of the positioning plate to improve working stability. The addition of a positioning seat can accurately align the lower mold moving plate.

[0023] As a preferred solution of the present invention, the positioning device comprises a positioning cylinder and a positioning column, wherein the positioning cylinder is vertically arranged on the workbench, and the piston rod of the positioning cylinder faces upward, and the positioning column is arranged on the piston rod of the positioning cylinder;

[0024] As a preferred solution of the present invention, the propulsion device comprises a propulsion cylinder, a driving frame, a mounting plate and a bracket, the mounting plate is fixed to the oblique combing plate, the mounting plate is fixed to the upper end of the bracket, the lower end of the bracket is movably arranged on a lateral linear guide rail, one end of the driving frame is connected to the mounting plate, and the other end is connected to the piston rod of the propulsion cylinder;

[0025] As a preferred solution of the present invention, the conveying device comprises a conveying cylinder and a fixed seat, the cylinder body of the conveying cylinder is fixed to the workbench through the fixed seat, and the piston rod of the conveying cylinder is connected to the lower mold moving plate;

[0026] As a preferred solution of the present invention, the lifting device includes a lifting seat and a lifting cylinder, the two lifting seats are symmetrically arranged on the workbench at the positions on both sides of the center line guide rail, the lifting cylinder is vertically arranged on the lifting seat, and the piston rod of the lifting cylinder is arranged in a direction and connected to the positioning plate;

[0027] As a preferred solution of the present invention, the angle a is 20 to 80 degrees.

[0028] The beneficial effects of the present invention are as follows: the oblique comb guide roller riveting method provided by the present invention is simple to operate and easy to implement. Before the cover plate is covered, all the blown plates are combed and aligned in advance by the oblique comb plate, and the combing and straightening angle of the oblique comb plate is consistent with the oblique arrangement angle of the blown plates, ensuring the combing and straightening effect. After the cover plate is covered, each rivet protrusion on the blown plate can be aligned with the rivet holes on the cover plate one by one, effectively improving the accuracy of the fitting assembly, ensuring the riveting effect, and ensuring the product quality. At the same time, it also eliminates the traditional manual adjustment and straightening process of the blown plates, saving time and effort, not only improving work efficiency, but also ensuring the consistency of the riveting effect and improving the yield rate. The operation is simple, convenient and easy to implement.

[0029] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the top view of the structure of the oblique comb guide roller riveting device of the present invention.

[0031] Figure 2 It is a three-dimensional structural schematic diagram of the oblique comb guide roller riveting device of the present invention.

[0032] Figure 3 It is a structural schematic diagram of the positioning plate and the center guide plate in the present invention.

[0033] Figure 4 It is a structural schematic diagram of the oblique comb plate in the present invention.

[0034] Figure 5 It is a structural schematic diagram of the aluminum plate base placed on the lower mold moving plate in the present invention.

[0035] Figure 6 yes Figure 5 Schematic diagram of the top view structure.

[0036] Figure 7 It is a structural schematic diagram of the lower mold movable plate moving to the assembly position in the present invention.

[0037] Figure 8 It is a structural schematic diagram of the process in which the oblique combing plate in the present invention combs and straightens the blowing plate.

[0038] Fig. 9 It is a schematic diagram of the structure after the oblique combing plate of the present invention completes combing and straightening.

[0039] Fig.10 It is a schematic diagram of the structure of the present invention when the cover plate is ready to be covered. DETAILED DESCRIPTION

[0040] See also Figures 1 to 10 The oblique comb guide roller riveting device provided in this embodiment is only used to illustrate the oblique comb guide roller riveting method of the present invention, but is not limited thereto. Other structural devices can also be used to implement the oblique comb guide roller riveting method. Before riveting, the inflation plate 13 is pre-riveted on the aluminum plate base 14, and rivet holes corresponding to the rivet protrusions of the inflation plate 13 are pre-set on the cover plate 15.

[0041] An oblique comb guide roller riveting device, comprising a workbench 1, a lower die moving plate 2, a positioning device 3, an oblique comb plate 4, a propulsion device 5, a conveying device 6, a lifting device 7, a positioning plate 8, a positioning seat 9 and a center guide plate 10, wherein the workbench 1 is provided with a center line guide rail 11, the lower die moving plate 2 is movably arranged on the center line guide rail 11, the conveying device 6 is arranged on the workbench 1, and can drive the lower die moving plate 2 to make a reciprocating motion on the center line guide rail 11, the workbench 1 is provided with a lateral linear guide rail 12 at a side position corresponding to the center line guide rail 11, and the side linear guide rail 12 is provided on the side of the workbench 1. There is an included angle a between the side linear guide rail 12 and the center line guide rail 11; the oblique combing plate 4 is movably arranged on the side linear guide rail 12; the propulsion device 5 is arranged on the workbench 1, and can drive the oblique combing plate 4 to make reciprocating motion on the side linear guide rail 12; the positioning plate 8 is arranged on the surface of the workbench 1 through the lifting device 7 corresponding to the position of the lower mold moving plate 2 moving to the assembly position; the positioning device 3 is arranged on the surface of the workbench 1 corresponding to the position of the lower mold moving plate 2 moving to the assembly position, and a positioning hole compatible with the positioning device 3 can be provided on the lower mold moving plate 2.

[0042] The positioning seat 9 is arranged at the end position of the center line guide rail 11. One end of the center guide plate 10 is fixed on the positioning seat 9, and the other end extends to the middle position of the positioning plate 8. The middle of the positioning plate 8 is provided with a sliding groove 81 adapted to the center guide plate 10; the lower mold moving plate 2 is provided with a positioning recess adapted to the positioning seat 9. The positioning plate 8 is provided with a side positioning inclined protrusion 82 adapted to the combing groove when the oblique combing plate 4 slides to the center position of the aluminum plate base 14. The center guide plate 10 extending along the moving trajectory line of the lower mold moving plate 2 is provided through the positioning seat 9 on the center line of the assembly position. The side wall of the center guide plate 10 is provided with a center positioning inclined protrusion 101 adapted to the combing groove when the oblique combing plate 4 slides to the center position of the aluminum plate base 14. The addition of the center guide plate 10 can position and fix the oblique combing plate 4 after combing and straightening to avoid displacement, and cooperate with the lifting action of the positioning plate 8 to improve working stability. The positioning seat 9 is additionally provided to accurately align the lower mold moving plate 2. The lower mold moving plate 2 is provided with a positioning recess that matches the positioning seat 9. Preferably, a contact convex point 41 is provided on the groove wall of the combing groove of the oblique combing plate 4. The contact convex point 41 contacts the inflation plate 13, and the friction force is reduced by reducing the contact area, which is more conducive to the smooth movement of the oblique combing plate 4.

[0043] Specifically, the positioning device 3 includes a positioning cylinder and a positioning column. The positioning cylinder is vertically arranged on the workbench 1, and the piston rod of the positioning cylinder faces upward. The positioning column is arranged on the piston rod of the positioning cylinder.

[0044] The propulsion device 5 includes a propulsion cylinder, a driving frame, a mounting plate and a bracket. The mounting plate is fixed to the oblique combing plate 4. The mounting plate is fixed to the upper end of the bracket. The lower end of the bracket is movably arranged on the lateral linear guide rail 12. One end of the driving frame is connected to the mounting plate, and the other end is connected to the piston rod of the propulsion cylinder.

[0045] The conveying device 6 includes a conveying cylinder and a fixed seat, the cylinder body of the conveying cylinder is fixed on the workbench 1 through the fixed seat, and the piston rod of the conveying cylinder is connected to the lower mold moving plate 2;

[0046] The lifting device 7 includes a lifting seat 71 and a lifting cylinder 72. The two lifting seats 71 are symmetrically arranged on the workbench 1 at the positions on both sides of the center line guide rail 11. The lifting cylinder 72 is vertically arranged on the lifting seat 71, and the piston rod of the lifting cylinder 72 is arranged in a direction and connected to the positioning plate 8. In other embodiments, the positioning cylinder, the propulsion cylinder, the conveying cylinder and the lifting seat 71 can be replaced by an oil cylinder, a linear motor or other devices with a linear drive function.

[0047] During operation, the steps of the oblique comb guide roller riveting method of the present invention are as follows:

[0048] (1) See Figure 5 and Figure 6 , the aluminum plate base 14 with the blowing plate 13 riveted thereon is placed on the lower mold moving plate 2, and a positioning block for positioning the aluminum plate base 14 is provided on the lower mold moving plate 2, and the area formed by the positioning block is just adapted to the outer contour of the aluminum plate base 14; wherein the direction of the blowing plate 13 forms an angle a with the moving trajectory of the lower mold moving plate 2; the angle a is 20 to 80 degrees, and in this embodiment, the angle a is 30 degrees;

[0049] (2) See Figure 7 , the conveying cylinder retracts, pulling the lower die moving plate 2 forward, and the lower die moving plate 2 is accurately positioned at the assembly position through the positioning seat 9;

[0050] (3) The positioning cylinder in the positioning device 3 extends out, driving the positioning column upward to be inserted into the bottom surface positioning hole of the lower mold moving plate 2, thereby achieving the purpose of fixing the position of the lower mold moving plate 2 through the positioning device 3;

[0051] (4) The lifting cylinder 72 in the lifting device 7 retracts to drive the positioning plate 8 to move downward to the rear side of the blowing plate 13, thereby achieving the purpose of moving the positioning plate 8 to the rear side of the blowing plate 13; during the lifting process, the positioning plate 8 cooperates with the central guide plate 10 through the sliding groove 81 on the positioning plate 8, so the lifting action is stable and accurate;

[0052] (5) See Figure 8 and Fig. 9 , the propulsion cylinder in the propulsion device 5 is retracted, and the oblique combing plate 4 is pulled by the driving frame to gradually slide along the angle a from the outer edge of the aluminum plate base 14 to the center position of the aluminum plate base 14, and the oblique combing plate 4 is pressed against the positioning plate 8, and the center positioning oblique protrusion 101 on the center guide plate 10 is inserted into the combing groove of the oblique combing plate 4, and the center guide plate 10 is used to accurately position the oblique combing plate 4 after combing and straightening; the oblique combing plate 4 uses the combing groove on it to comb and straighten the blowing plate 13 during the sliding process, so that the rivet protrusions on the blowing plate 13 are all positioned at the predetermined positions; the blowing plates 13 are divided into two groups, which are symmetrically distributed on both sides of the center line of the aluminum plate base 14, and a central slot for the center guide plate 10 to extend into is formed between the two groups of blowing plates 13;

[0053] (6) See Fig.10 , the cover plate 15 is covered on the inflation plate 13, and each rivet protrusion on the inflation plate 13 can be aligned and matched with the rivet holes on the cover plate 15 one by one, that is, all the rivet protrusions on the inflation plate 13 can be accurately inserted into the rivet holes on the cover plate 15 at the same time;

[0054] (7) Riveting the rivet protrusions on the blown plate 13 by means of upper die downward pressure, rolling riveting equipment or hammer, so that the cover plate 15 is riveted on the blown plate 13 to obtain a riveted product;

[0055] (8) The propulsion cylinder in the propulsion device 5 extends out, and pushes the oblique comb plate 4 back to the initial position through the drive frame;

[0056] (9) The lifting cylinder 72 extends to push the positioning plate 8 upward and back to the initial position, so that there is enough space for the lower mold moving plate 2 to push in or push out;

[0057] (10) The positioning cylinder retracts, driving the positioning column to be limited out of the positioning hole, so that the positioning device 3 releases the lower mold moving plate 2;

[0058] (11) The conveying cylinder extends to push the lower die moving plate 2 back until the lower die moving plate 2 returns to its initial position, and the riveted product is taken out;

[0059] (12) Repeat steps (1)-(11) to implement a new round of oblique comb guide roller riveting process. The oblique comb guide roller riveting method provided by the present invention is simple to operate and easy to implement. Before covering the cover plate 15, all the blowing plates 13 are combed and aligned by the oblique comb plate 4 in advance, and the combing and straightening angle of the oblique comb plate 4 is consistent with the oblique arrangement angle of the blowing plate 13 to ensure the combing and straightening effect. After covering the cover plate 15, each rivet protrusion on the blowing plate 13 can be aligned with the rivet hole on the cover plate 15 one by one, effectively improving the accuracy of the fitting assembly, ensuring the riveting effect, and ensuring the product quality. At the same time, it also saves the traditional manual adjustment and straightening process of the blowing plate 13, saving time and labor, not only improving work efficiency, but also ensuring the consistency of the riveting effect and improving the yield rate.

[0060] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above implementation. Therefore, the present invention is not limited to the specific implementation disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention. As described in the above embodiment of the present invention, other riveting methods and devices obtained by using the same or similar structure are all within the protection scope of the present invention.

Claims

1. An oblique comb-guided roller riveting method, characterized in that: It includes the following steps: (1) placing an aluminum plate base riveted with a blown plate on a lower mold movable plate; wherein the direction of the blown plate forms an angle a with the moving trajectory of the lower mold movable plate; (2) Push the lower mold moving plate to the assembly position; (3) The positioning device fixes the position of the lower mold moving plate; (4) The positioning plate is moved to the rear side of the blowing plate; (5) The oblique combing plate gradually slides from the outer edge of the aluminum plate base to the center of the aluminum plate base along the included angle a, and the oblique combing plate is pressed against the positioning plate. During the sliding process, the oblique combing plate uses the combing groove on it to comb and straighten the blowing plate, so that the rivet protrusions on the blowing plate are all positioned at the predetermined positions; (6) Put the cover plate on the inflation plate, and the rivet protrusions on each inflation plate can be aligned and matched with the rivet holes on the cover plate one by one; (7) Riveting the rivet protrusions on the blown plate to achieve riveting of the cover plate on the blown plate to obtain a riveted product; A centerline guide rail is provided on the workbench, the lower mold movable plate is movably arranged on the centerline guide rail, the conveying device is arranged on the workbench, and can drive the lower mold movable plate to make reciprocating motion on the centerline guide rail, the workbench is provided with a lateral linear guide rail at the side position corresponding to the centerline guide rail, the lateral linear guide rail and the centerline guide rail form an included angle a, the oblique combing plate is movably arranged on the lateral linear guide rail, the propulsion device is arranged on the workbench, and can drive the oblique combing plate to make reciprocating motion on the lateral linear guide rail; the positioning plate is arranged on the workbench through a lifting device at a position corresponding to the lower mold movable plate moving to the assembly position; the positioning device is arranged on the workbench at a position corresponding to the lower mold movable plate moving to the assembly position, and a positioning hole adapted to the positioning device is provided on the lower mold movable plate.

2. The oblique comb guide roller riveting method according to claim 1, characterized in that: It also includes the following steps: (8) The oblique comb plate returns to its initial position; (9) The positioning plate returns to its initial position; (10) The positioning device releases the lower mold moving plate; (11) The lower die moving plate returns to its initial position and the riveted product is taken out; (12) Repeat steps (1) to (11) to complete a new round of oblique comb-guided roller riveting process.

3. The oblique comb guide roller riveting method according to claim 1 or 2, characterized in that: The angle a is 20 to 80 degrees.

4. The oblique comb guide roller riveting method according to claim 1, characterized in that: A center guide plate extending along the moving trajectory of the lower mold movable plate is provided on the center line of the assembly position through the positioning seat. The lower mold movable plate is provided with a positioning recess matched with the positioning seat. The positioning seat is used to accurately position the lower mold movable plate when it is moved to the assembly position; the center guide plate is used to accurately position the oblique combing plate after combing and straightening.

5. The oblique comb guide roller riveting method according to claim 4, characterized in that: The inflation plates are divided into two groups, which are symmetrically distributed on both sides of the center line of the aluminum plate base, and a center slot is formed between the two groups of inflation plates for the center guide plate to extend into.

6. The oblique comb guide roller riveting method according to claim 5, characterized in that: The side wall of the central guide plate is provided with a central positioning oblique protrusion which is matched with the combing groove when the oblique combing plate slides to the central position of the aluminum plate base.

7. The oblique comb guide roller riveting method according to claim 6, characterized in that: The positioning plate is provided with a side positioning oblique protrusion which is matched with the combing groove when the oblique combing plate slides to the center position of the aluminum plate base, and the positioning plate is provided with a sliding groove which is matched with the center guide plate.

8. The oblique comb guide roller riveting method according to claim 1, characterized in that: It also includes a positioning seat and a center guide plate. The positioning seat is arranged at the end position of the center line guide rail. One end of the center guide plate is fixed on the positioning seat, and the other end extends to the middle position of the positioning plate. The middle of the positioning plate is provided with a sliding groove that is compatible with the center guide plate; the lower mold moving plate is provided with a positioning recess that is compatible with the positioning seat.

9. The oblique comb guide roller riveting method according to claim 1 or 8, characterized in that: The positioning device comprises a positioning cylinder and a positioning column, wherein the positioning cylinder is vertically arranged on the workbench, and the piston rod of the positioning cylinder faces upward, and the positioning column is arranged on the piston rod of the positioning cylinder; The propulsion device comprises a propulsion cylinder, a driving frame, a mounting plate and a bracket, wherein the mounting plate is fixed to the oblique combing plate, the mounting plate is fixed to the upper end of the bracket, the lower end of the bracket is movably arranged on a lateral linear guide rail, one end of the driving frame is connected to the mounting plate, and the other end is connected to the piston rod of the propulsion cylinder; The conveying device comprises a conveying cylinder and a fixing seat, the cylinder body of the conveying cylinder is fixed on the workbench through the fixing seat, and the piston rod of the conveying cylinder is connected to the lower mold moving plate; The lifting device comprises a lifting seat and a lifting cylinder. The two lifting seats are symmetrically arranged on the workbench at the positions on both sides of the center line guide rail. The lifting cylinder is vertically arranged on the lifting seat, and the piston rod of the lifting cylinder is arranged in a direction and connected to the positioning plate. The angle a is 20 to 80 degrees.

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