Integrated tensioning structure of chain saw

Abstract

The utility model belongs to the technical field of chain saws, and particularly relates to an integrated tensioning structure of a chain saw, which comprises a first knob and a second knob, an elastic sheet is arranged in the second knob, a notch for the protruding part of the elastic sheet to extend out is arranged on the side wall of the second knob, and a ratchet wheel groove is arranged on the inner side wall of the first knob. When the protruding part extends out of the notch and abuts against the end of the ratchet wheel groove, the first knob drives the second knob to rotate. When the first knob rotates reversely, the second knob does not rotate. The utility model has the advantages of few parts, convenience in installation and low cost; and meanwhile, tensioning of the chain can be accurately controlled, and the situation that the chain is not tensioned tightly or is tensioned too tightly is avoided.

Description

Technical Field:

[0001] The utility model belongs to the technical field of chain saws, and particularly refers to an integrated tensioning structure of a chain saw. Background Art:

[0002] The Chinese utility model patent (publication number CN204975540U, application date July 27, 2015, publication date January 20, 2016) discloses an electric chain saw with an integrated chain locking structure, including an electric chain saw housing. A first knob is installed on the electric saw chain housing. A second knob is sleeved inside the first knob. Both the first knob and the second knob are connected to a nut, and the nut is connected to a bolt. The bolt passes through a spiral plate, an adjusting plate, and a chain plate in sequence and then is connected to the electric saw chain housing. A steel ball rolling slide rail is provided inside the first knob, and a steel ball is installed in the steel ball rolling slide rail. A spring is installed between the second knob and the steel ball, and the second knob is in contact connection with the first knob through the steel ball. When the electric chain saw is in use, since the second knob is in contact connection with the first knob through the steel ball, when the friction force between the first knob and the steel ball is greater than the rotation resistance of the second knob, the first knob drives the second knob to rotate together with the first knob; when the friction force between the first knob and the steel ball is less than the rotation resistance of the second knob, the second knob stops rotating and the first knob continues to rotate, thereby realizing the adjustment of the tightness between the chain plate and the chain and locking the chain plate and the chain at the same time.

[0003] The deficiencies of the above-mentioned electric chain saw are as follows: 1. The first knob drives the second knob to rotate together through steel beads and a spring, with many parts, inconvenient for installation and high cost; 2. There is a high requirement for the spring stiffness of the spring. When the spring stiffness is small, the friction force between the first knob and the steel ball is small and the chain cannot be tightened; when the spring stiffness is large, the friction force between the first knob and the steel ball is large and the chain is tightened too much, resulting in the chain saw being unable to start. However, in the processing process, it is often difficult to accurately control the spring stiffness of the spring. Summary of the Invention:

[0004] The purpose of the utility model is to provide an integrated tensioning structure of a chain saw, which has few parts, is convenient for installation and has low cost; at the same time, it can accurately control the tension of the chain and will not occur the situation that the chain cannot be tightened or is tightened too much.

[0005] The utility model is realized as follows:

[0006] An integrated tensioning structure of a chain saw includes a first knob and a second knob. A shrapnel is provided inside the second knob, and a notch for the protruding part of the shrapnel to extend out is provided on the side wall of the second knob. A ratchet groove is provided on the inner side wall of the first knob. When the first knob rotates forward and the protruding part extends out of the notch and abuts against the end of the ratchet groove, the first knob drives the second knob to rotate; when the first knob rotates backward, the second knob does not rotate.

[0007] In the above-mentioned integrated tensioning structure of a chainsaw, two or more elastic pieces are evenly distributed in the circumferential direction.

[0008] In the above-mentioned integrated tensioning structure of a chainsaw, a support portion that abuts against the inner end of the elastic piece is provided inside the second knob. The elastic piece includes a mounting portion whose inner end abuts against the support portion, and an elastic portion that connects the mounting portion and the protruding portion.

[0009] In the above-mentioned integrated tensioning structure of a chainsaw, a limiting portion that abuts against the outer end of the elastic portion is provided on the second knob. The limiting portion is located on the outer circumference of the support portion, and a mounting groove for installing the elastic piece is left between the limiting portion and the support portion. The notch is provided on the limiting portion.

[0010] In the above-mentioned integrated tensioning structure of a chainsaw, the limiting portion and the support portion are circular arc plates arranged coaxially.

[0011] In the above-mentioned integrated tensioning structure of a chainsaw, the protruding portion is in a U shape with an opening facing inward. There are two elastic portions, which are respectively connected to both ends of the protruding portion, and two corresponding mounting portions are provided.

[0012] In the above-mentioned integrated tensioning structure of a chainsaw, the two side walls of the notch are gradually inclined towards the middle from the inside to the outside.

[0013] In the above-mentioned integrated tensioning structure of a chainsaw, it further includes a chain plate and an adjusting plate provided on the chain plate. A convex block is provided on the adjusting plate. Two semi-circular eccentric wheels are provided below the second knob, and the center connection line of the two semi-circular eccentric wheels passes through the rotation center of the second knob. When the second knob rotates and the outer circumference of the semi-circular eccentric wheel abuts against the convex block, the semi-circular eccentric wheel pushes the convex block and the chain plate to move and tension the chain.

[0014] In the above-mentioned integrated tensioning structure of a chainsaw, the two semi-circular eccentric wheels are of an integrated structure, and a screw passes through the second knob and is screwed to the semi-circular eccentric wheel.

[0015] In the above-mentioned integrated tensioning structure of a chainsaw, it further includes a chainsaw housing and a side cover. The chain plate is slidably arranged on the chainsaw housing. A bolt is provided on the chainsaw housing, and the rod portion of the bolt sequentially passes through the chain plate and the adjusting plate and extends out. A nut that is screwed to the bolt is provided inside the first knob. The upper end of the nut is connected to the first knob, and a snap ring is provided at the lower end. The second knob is sleeved on the nut and is limited between the first knob and the snap ring. An axial movement gap is left between the second knob and the first knob. An installation convex edge is provided on the outer circumference of the second knob. The side cover is arranged between the first knob and the installation convex edge.

[0016] In the above-mentioned integrated tensioning structure of a chainsaw, a pressing plate for upper limiting the elastic piece is provided on the second knob.

[0017] In the above-mentioned integral tensioning structure of a chain saw, a screw passes through a pressing plate and is screwed to a second knob.

[0018] The prominent advantages of the present utility model compared with the prior art are as follows:

[0019] 1. In the present utility model, the first knob drives the second knob to rotate together only through an elastic piece. There are few parts, which is convenient for installation and has a low cost. At the same time, the distance that the protruding part of the elastic piece protrudes from the first knob is convenient to be accurately controlled by controlling the size of the elastic piece. Therefore, the tension of the chain can be accurately controlled, and the situation that the chain is not tightened or tightened too much will not occur.

[0020] 2. The outer end of the elastic part of the present utility model abuts against and is limited by the limiting part arranged on the second knob, effectively preventing the elastic piece from coming out of the second knob, which is convenient for installation. Description of the drawings:

[0021] Figure 1 is a cross-sectional view of the chainless saw housing, chain plate and side cover of the present utility model;

[0022] Figure 2 is a perspective view of the chainless saw housing, chain plate and side cover of the present utility model;

[0023] Figure 3 is an exploded view of the chainless saw housing, chain plate, pressing plate and side cover of the present utility model Figure 1 ;

[0024] Figure 4 is an exploded view of the chainless saw housing, chain plate, pressing plate and side cover of the present utility model Figure 2 ;

[0025] Figure 5 is a cross-sectional view of the present utility model;

[0026] Figure 6 is a perspective view of the present utility model.

[0027] Reference numerals: 1. First knob; 2. Second knob; 3. Elastic piece; 3a. Protruding part; 3b. Installation part; 3c. Elastic part; 4. Notch; 5. Ratchet groove; 6. Support part; 7. Limiting part; 8. Installation groove; 9. Chain plate; 10. Adjusting plate; 11. Protruding block; 12. Semi-circular eccentric wheel; 13. Chain saw housing; 14. Side cover; 15. Bolt; 16. Nut; 17. Snap ring; 18. Installation convex edge; 19. Pressing plate. Detailed implementation manners:

[0028] The following further describes the present utility model with specific embodiments. Refer to Figure 1 -6:

[0029] An integrated tensioning structure for a chainsaw, comprising a first knob 1 and a second knob 2. A shrapnel 3 is provided inside the second knob 2, and a notch 4 for the protruding portion 3a of the shrapnel 3 to extend out is provided on the side wall of the second knob 2. A ratchet groove 5 is provided on the inner side wall of the first knob 1. When the first knob 1 rotates forward and the protruding portion 3a extends out of the notch 4 and abuts against the end of the ratchet groove 5, the first knob 1 drives the second knob 2 to rotate; when the first knob 1 rotates in reverse, the second knob 2 does not rotate.

[0030] The working principle of the present utility model: As Figures 1-6 shown, the protruding portion 3a of the shrapnel 3 extends out of the notch 4 of the second knob 2. When the first knob 1 rotates forward and the protruding portion 3a abuts against the end of the ratchet groove 5, the first knob 1 drives the second knob 2 to rotate together until the rotational resistance of the second knob is large enough, and then the protruding portion 3a of the shrapnel 3 retracts under the push of the first knob 1, and the second knob 2 stops rotating; when the first knob 1 rotates in reverse, the protruding portion 3a of the shrapnel 3 retracts under the guidance of the groove wall of the ratchet groove 5, and the second knob 2 does not rotate.

[0031] In the present utility model, the first knob 1 drives the second knob 2 to rotate together only through the shrapnel 3, with fewer parts, convenient installation, and low cost; at the same time, the present utility model controls the distance that the protruding portion 3a of the shrapnel 3 protrudes from the first knob 1, controls the thrust force for the protruding portion 3a to retract, and thus accurately controls the tension of the chain. Since the distance that the protruding portion 3a of the shrapnel 3 protrudes from the first knob 1 is convenient to be accurately controlled by controlling the size of the shrapnel 3, therefore, the present utility model can accurately control the tension of the chain and will not occur the situation that the chain is not tightened or is tightened too much.

[0032] Preferably, two or more shrapnels 3 are circumferentially and uniformly distributed. In this embodiment, three shrapnels 3 are circumferentially and uniformly distributed.

[0033] The structure of the shrapnel 3 and the installation structure: As Figures 1-4 shown, a support portion 6 that abuts against the inner end of the shrapnel 3 is provided inside the second knob 2. The shrapnel 3 includes an installation portion 3b with an inner end abutting against the support portion 6, and an elastic portion 3c connecting the installation portion 3b and the protruding portion 3a.

[0034] Furthermore, a limiting portion 7 that abuts against the outer end of the elastic portion 3c is provided on the second knob 2. The limiting portion 7 is located on the outer circumference of the support portion 6, and a mounting groove 8 for installing the shrapnel 3 is left between the limiting portion 7 and the support portion 6. The notch 4 is provided on the limiting portion 7. In the prior art, during installation, the steel ball is easily detached from the second knob, which is not convenient for installation. In the present utility model, the outer end of the elastic portion 3c abuts against and is limited by the limiting portion 7 provided on the second knob 2, effectively preventing the shrapnel 3 from detaching from the second knob 2 and facilitating installation.

[0035] Preferably, the limiting part 7 and the supporting part 6 are circular arc plates arranged coaxially.

[0036] Specific structure of the elastic piece 3: The protruding part 3a is U-shaped with an opening facing inwards. There are two elastic parts 3c, which are respectively connected to both ends of the protruding part 3a, and correspondingly, there are two mounting parts 3b.

[0037] Furthermore, both side walls of the notch 4 are gradually inclined towards the middle from the inside to the outside, which is convenient for installation and further prevents the elastic piece 3 from coming out.

[0038] Furthermore, it further includes a chain plate 9 and an adjusting plate 10 arranged on the chain plate 9. The adjusting plate 10 is provided with a convex block 11. There are two semi-circular eccentric wheels 12 below the second knob 2, and the center line connecting the centers of the two semi-circular eccentric wheels 12 passes through the rotation center of the second knob 2. When the second knob 2 rotates and the outer periphery of the semi-circular eccentric wheel 12 abuts against the convex block 11, the semi-circular eccentric wheel 12 pushes the convex block 11 and the chain plate 9 to move and tension the chain.

[0039] Working principle of the chain tensioning of the present utility model: When the first knob 1 rotates to drive the second knob 2 to rotate, the outer periphery of the semi-circular eccentric wheel 12 abuts against the convex block 11, pushing the convex block 11 to move in a direction away from the rotation center of the second knob 2, and further driving the chain plate 9 to move in a direction away from the rotation center of the second knob 2, thereby realizing the tensioning of the chain.

[0040] The present utility model is provided with two semi-circular eccentric wheels 12, so that when the second knob 2 rotates one circle, there are two chances to abut against the convex block 11, which is convenient for pushing the convex block 11 to move and convenient for tensioning the chain.

[0041] Installation structure of the semi-circular eccentric wheel 12: The two semi-circular eccentric wheels 12 are of an integral structure, and a screw passes through the second knob 2 and is threadedly connected to the semi-circular eccentric wheel 12.

[0042] Furthermore, it further includes a chain saw housing 13 and a side cover 14. The chain plate 9 is slidably arranged on the chain saw housing 13. The chain saw housing 13 is provided with a bolt 15, and the rod part of the bolt 15 sequentially passes through the chain plate 9 and the adjusting plate 10 and extends out. A nut 16 threadedly connected to the bolt 15 is arranged inside the first knob 1. The upper end of the nut 16 is connected to the first knob 1, and a circlip 17 is arranged at the lower end. The second knob 2 is sleeved on the nut 16 and is limited between the first knob 1 and the circlip 17. There is an axial movement gap between the second knob 2 and the first knob 1. An installation convex edge 18 is arranged on the outer periphery of the second knob 2, and the side cover 14 is arranged between the first knob 1 and the installation convex edge 18.

[0043] Rotating the first knob 1 clockwise causes the nut 16 to be screwed onto the bolt 15, gradually reducing the axial clearance between the second knob 2 and the first knob 1 until the semi-circular eccentric wheel 12 is pressed against the adjusting plate 10. Rotating the first knob 1 counterclockwise, the first knob 1 moves upward, gradually increasing the axial clearance between the second knob 2 and the first knob 1. The first knob 1 rotates relative to the second knob 2 until the nut 16 is unscrewed from the bolt 15, and then the first knob 1 and the second knob 2 are removed.

[0044] To prevent the elastic piece 3 from coming out, a pressing plate 19 for limiting the upward position of the elastic piece 3 is provided on the second knob 2.

[0045] The installation structure of the pressing plate 19: The screw passes through the pressing plate 19 and is screwed onto the second knob 2.

[0046] The above embodiments are only one of the preferred embodiments of the present invention, and do not limit the scope of implementation of the present invention. Therefore, all equivalent changes made according to the shape, structure, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. An integrated tensioning structure for a chainsaw, comprising a first knob (1) and a second knob (2), characterized in that: A shrapnel (3) is provided inside the second knob (2). A notch (4) is provided on the side wall of the second knob (2) for the protruding portion (3a) of the shrapnel (3) to protrude. A ratchet groove (5) is provided on the inner side wall of the first knob (1). When the first knob (1) rotates forward and the protruding portion (3a) protrudes from the notch (4) and abuts against the end of the ratchet groove (5), the first knob (1) drives the second knob (2) to rotate; when the first knob (1) rotates in reverse, the second knob (2) does not rotate.

2. The integrated tensioning structure of a chain saw according to claim 1, characterized in that: A support portion (6) that abuts against the inner end of the shrapnel (3) is provided inside the second knob (2). The shrapnel (3) includes a mounting portion (3b) whose inner end abuts against the support portion (6), and an elastic portion (3c) that connects the mounting portion (3b) and the protruding portion (3a).

3. The one-piece tensioning structure of a chain saw according to claim 2, characterized in that: A limiting portion (7) that abuts against the outer end of the elastic portion (3c) is provided on the second knob (2). The limiting portion (7) is located on the outer periphery of the support portion (6), and an installation groove (8) for installing the shrapnel (3) is left between the limiting portion (7) and the support portion (6). The notch (4) is provided on the limiting portion (7).

4. The integrated tensioning structure of a chain saw according to claim 3, characterized in that: The protruding portion (3a) is U-shaped with an opening facing inward. There are two elastic portions (3c), which are respectively connected to both ends of the protruding portion (3a), and two corresponding mounting portions (3b) are provided.

5. The one-piece tensioning structure of a chain saw according to claim 4, characterized in that: The two side walls of the notch (4) gradually incline towards the middle from inside to outside.

6. The one-piece tensioning structure of a chain saw according to claim 1, characterized in that: It further includes a chain plate (9) and an adjusting plate (10) provided on the chain plate (9). A convex block (11) is provided on the adjusting plate (10). Two semi-circular eccentric wheels (12) are provided below the second knob (2), and the center line connecting the centers of the two semi-circular eccentric wheels (12) passes through the rotation center of the second knob (2). When the second knob (2) rotates and the outer periphery of the semi-circular eccentric wheel (12) abuts against the convex block (11), the semi-circular eccentric wheel (12) pushes the convex block (11) and the chain plate (9) to move and tension the chain.

7. The integrated tensioning structure of a chain saw according to claim 6, wherein: It further includes a chainsaw housing (13) and a side cover (14). The chain plate (9) is slidably arranged on the chainsaw housing (13). A bolt (15) is provided on the chainsaw housing (13). The rod portion of the bolt (15) sequentially passes through the chain plate (9) and the adjusting plate (10) and extends out. A nut (16) that is threadedly connected to the bolt (15) is provided inside the first knob (1). The upper end of the nut (16) is connected to the first knob (1), and a snap ring (17) is provided at the lower end. The second knob (2) is sleeved on the nut (16) and is limited between the first knob (1) and the snap ring (17). An axial movement gap is left between the second knob (2) and the first knob (1). An installation convex edge (18) is provided on the outer periphery of the second knob (2). The side cover (14) is arranged between the first knob (1) and the installation convex edge (18).

8. The integrated tensioning structure of a chain saw according to claim 1, characterized in that: A pressing plate (19) for upper limiting the shrapnel (3) is provided on the second knob (2).

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