Saw chain riveting structure for lumbering

Abstract

The invention belongs to the technical field of saw chains, and particularly relates to a saw chain riveting structure for lumbering, which comprises a pin shaft and an outer plate component riveted with the pin shaft, the outer plate component is provided with a hole structure used for being in interference fit with the pin shaft, the hole structure is a counter bore, the inner wall of the large-diameter section of the counter bore is laterally cut into an arc-shaped structure expanding outwards in the radial direction, and the outer plate component is provided with a through hole. The small-diameter section penetrates through the inner surface of the outer plate component; the pin shaft comprises an annular boss which is located in the middle and formed through diameter expansion, the two ends of the annular boss form connecting sections which are coaxially arranged, the connecting sections penetrate through the small-diameter sections, the ends of the connecting sections are filled in the large-diameter sections through the press riveting technology, and after press riveting, the top edges of the connecting sections are flush with the outer surface of the outer plate. The top end of the connecting section is of a spherical structure protruding upwards, the connecting section is in interference fit with the small-diameter section, and the end of the connecting section is in interference fit with the large-diameter section. The strength of the riveting structure can be effectively improved, the service life of the saw chain is prolonged, and fatigue fracture or abrasion failure of the outer plate is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of saw chains, and in particular relates to a riveting structure of a saw chain for logging. Background Art

[0002] At present, existing chainsaw chains are all riveted externally. It has been verified that the main failure forms of chainsaw chains are fatigue fracture of the outer plate, wear failure between the outer plate and the pin shaft, and wear and tear between the rivet head and the wood, resulting in the rivet head being worn flat. After careful research by the applicant, it was found that the main cause of failure is the riveting structure of the chainsaw chain. Specifically:

[0003] like Figure 4 As shown in a, it is the riveted structure before improvement. The end of the pin shaft is deformed by the vertical downward pressure to form a rivet head. The inner surface of the rivet head is attached to the surface of the outer plate. During the downward pressure application process, the upper part of the pin shaft connecting section in the outer plate hole structure expands and deforms. Due to the expansion deformation, the outer plate hole structure is squeezed to expand, and a gap is formed between the lower surface of the connecting section and the inner wall of the hole structure. This actually leads to the connecting section of the pin shaft partially achieving an interference fit with the hole structure, while most of the structure has a gap with the hole structure, resulting in a significant reduction in the contact area between the connecting section and the inner wall of the hole structure of the outer plate, which leads to stress concentration in the outer plate hole. In actual use, tiny cracks appear, which leads to rapid fatigue fracture or wear failure of the outer plate. At the same time, since the rivet head is located on the outside of the outer plate, the rivet head constantly rubs against the wood during the wood cutting process. Long-term use will cause the rivet head to be worn off, which will lead to the failure of the saw chain.

[0004] In order to avoid the above problems, in the prior art, the outer diameter of the connecting section of the pin shaft is reduced so that it can fit with the hole structure when inserted into the hole structure, and the connecting section is compressed and expanded when passing through the rivet head to achieve interference fit. However, the effect is not ideal because: only the local structure at the top of the connecting section produces a significant expansion effect, which achieves interference fit, and the remaining part still has a gap with the hole structure, and thus the chain plate still breaks and fails due to wear. Summary of the invention

[0005] The invention discloses a riveting structure for a saw chain for felling trees, aiming to solve the problems of rapid fatigue fracture of an outer plate, wear failure between the outer plate and a pin shaft, and wear and tear failure of the rivet head caused by wear between the rivet head and wood in the existing riveting structure.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A riveted structure for a saw chain for logging, the riveted structure comprising a pin shaft and an outer plate component riveted together with the pin shaft, the outer plate component being provided with a hole structure for interference fit with the pin shaft, the hole structure being a countersunk hole, the inner wall side profile of the large diameter section of the countersunk hole being an arc-shaped structure expanding radially outward, and the small diameter section passing through the inner surface of the outer plate component; the pin shaft comprising an annular boss located in the middle and formed by diameter expansion, the two ends of the annular boss constituting a coaxially arranged connecting section, the connecting section passing through the small diameter section, the end of the connecting section being filled in the large diameter section by a riveting process, after riveting, the top edge of the connecting section being flush with the outer surface of the outer plate, the top end of the connecting section being an upwardly protruding spherical structure, the connecting section having an interference fit with the small diameter section, and the end of the connecting section having an interference fit with the large diameter section.

[0008] Preferably, the height of the large diameter section is 1 / 3 of the thickness of the outer plate.

[0009] Preferably, the portion where the annular boss is connected to the root of the connecting section is provided with a first chamfered structure, and the lower end of the small diameter section is provided with a second chamfered structure. After riveting, the first chamfered structure and the second chamfered structure are tightly matched.

[0010] Preferably, the outer plate comprises a left blade plate, a right blade plate and a connecting plate for assembling a saw chain, and the left blade plate, the right guide plate and the connecting plate are respectively provided with two hole structures for assembling pin shafts.

[0011] The beneficial effects of the riveting structure of a saw chain for logging of the present invention are:

[0012] In order to enhance the fatigue resistance of the outer plate of the oil saw chain, the present invention overcomes the limitations of traditional technology and improves the riveting structure. It has been verified that the present invention can greatly increase the contact area between the pin shaft connecting section and the outer plate hole structure, avoid the problems of rapid fatigue fracture and wear failure of the outer plate caused by stress concentration in the hole structure, and thus effectively enhance the structural strength of the saw chain, improve the stability during use, and extend the service life of the saw chain. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the saw chain structure involved in the present invention;

[0014] Figure 2 is a schematic diagram of the structure of the outer plate component;

[0015] Figure 3 This is a schematic diagram of the structure of the pin after riveting;

[0016] Figure 4 Schematic diagram of the riveting structure before (as shown in figure a) and after (as shown in figure b) improvement.

[0017] 01. Chain link unit one; 02. Chain link unit three; 03. Chain link unit two; 1. Left blade; 2. Right blade; 3. Middle guide tooth; 4. Connecting plate; 5. Pin; 6. Rivet head; 7. Annular boss; 8. Annular curved surface on the side of rivet head; 9. Countersunk hole; 10. Chamfered corner structure one; 11. Arc-shaped structure; 12. Chamfered corner structure two; 13. Downward pressure; 14. Radial expansion force when riveting head; 15. Spherical structure; 16. Clearance; 17. Position of interference fit. DETAILED DESCRIPTION

[0018] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0019] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0020] Example 1

[0021] A riveted structure for a saw chain used for logging, such as Figure 1-4 As shown, the riveted structure includes a pin shaft 5 and an outer plate member riveted together with the pin shaft 5. The outer plate member is relative to the middle guide tooth 3 of the saw chain. The members (connecting plate 4, left blade plate, right blade plate) outside the middle guide tooth 3 are outer plate members. The outer plate member is provided with a hole structure for interference fit with the pin shaft 5. The hole structure is a countersunk hole 9. The inner wall of the large diameter section of the countersunk hole 9 is a side section of an arc-shaped structure 11 expanding radially outward, and the small diameter section passes through the inner surface of the outer plate member; the pin shaft 5 includes an annular boss 7 located in the middle and formed by expanding the diameter, and the two ends of the annular boss 7 constitute a coaxially arranged connecting section ( Figure 3 The connecting section is formed by riveting, wherein the connecting section passes through the small diameter section, and the end of the connecting section is filled in the large diameter section by riveting process, such as Figure 4 As shown in b, after riveting, the top edge of the connecting section is flush with the outer surface of the outer plate, the top of the connecting section is a spherical structure 15 protruding upward, the connecting section is interference fit with the small diameter section, and the end of the connecting section is interference fit with the large diameter section.

[0022] Example 2

[0023] like Figure 4 As shown, the height of the large diameter section is 1 / 3 of the thickness of the outer plate. Figure 4As shown in a, it is a structural diagram of the existing riveted structure after being actually cut open. From the figure, it can be seen that in the actual use scenario, the gap 16 is formed after the pin shaft and the outer plate are riveted and formed. The specific principle is as described in the background technology part. After repeated observation by the applicant, it is found that the part of the connection section that is deformed by the downward pressure 13 is roughly at the upper 1 / 3 height of the hole structure. Therefore, the height of the large diameter section is set to 1 / 3 of the overall height of the hole structure, which is equivalent to 1 / 3 of the thickness of the outer plate structure. So that the diameter expansion section can fully accommodate the diameter expansion deformation of the connection section within this height range, and at the same time, the rivet head is riveted in the large diameter section.

[0024] Example 3

[0025] like Figure 3 As shown, the portion where the annular boss 7 is connected to the root of the connecting section is provided with a chamfered corner structure 10, and the lower end of the small diameter section is provided with a chamfered corner structure 2 12. After riveting, the chamfered corner structure 10 and the chamfered corner structure 2 12 fit tightly.

[0026] Example 4

[0027] like Figure 1 , 2 As shown, the outer plate includes a left blade plate 1, a right blade plate 2 and a connecting plate 4 for assembling a saw chain, and the left blade plate 1, the right guide plate 2 and the connecting plate 4 are respectively provided with two hole structures for assembling a pin 5.

[0028] Example 5

[0029] like Figure 1 , 2 As shown, the saw chain includes a link unit 101 consisting of a left blade plate 1, a connecting plate 4, two middle guide teeth 3, and two pins 5, a link unit 203 consisting of two oppositely arranged connecting plates 4 and two pins 5, and a link unit 302 consisting of a right blade plate 2, a connecting plate 4, two middle guide teeth 3, and two pins 5. The middle guide teeth 3 are provided with two connecting holes, and the connecting holes are clearance-matched with the annular boss 7 of the pins. The connecting sections at both ends of the pins 5 are respectively interference-fitted with the corresponding hole structures of the left blade plate 1, the right blade plate 2, and the connecting plate 4. The link unit 101 and the link unit 302 are alternately arranged and connected through the link unit 203.

[0030] like Figure 1 , 2As shown, in the chain link unit 101, the left blade plate 1 and the connecting plate 4 are arranged opposite to each other, and the two middle guide teeth 3 are respectively located on both sides. A pin shaft 5 is connected between the hole structures arranged opposite to each other on the left blade plate 1 and the connecting plate 4, and the annular boss 7 of the pin shaft 5 is clearance-matched with the connecting hole of the middle guide tooth 3 adjacent to the same side, and the connecting sections at both ends of the pin shaft 5 are respectively interference-fitted with the hole structures of the left blade plate 1 and the connecting plate 4; in the chain link unit 302, the right blade plate 2 and the connecting plate 4 are arranged opposite to each other, and the two middle guide teeth 3 are respectively located on both sides, and the right blade plate 2 and the connecting plate 4 are arranged opposite to each other A pin 5 is connected between the hole structures disposed therein, and the annular boss 7 of the pin 5 is clearance-matched with the connecting hole of the adjacent middle guide tooth 3 on the same side, and the connecting sections at both ends of the pin 5 are interference-fitted with the hole structures of the right knife plate 2 and the connecting plate 4 respectively; the chain link unit 2 03 is disposed between the chain link unit 1 01 and the chain link unit 3 02, and the connecting sections of the pin 5 of the chain link unit 2 03 respectively pass through the hole structures on the same side of the two oppositely disposed connecting plates 4 and are interference-fitted with the hole structures, and the annular boss of the chain link unit 2 03 is clearance-matched with the connecting hole of the adjacent middle guide tooth 3.

[0031] This embodiment provides a structural form of a saw chain, specifically, Figure 1 shown.

[0032] Working principle of the present invention:

[0033] like Figure 4 As shown in Fig. b, in the improved riveting structure, the connection section with expanded diameter and the rivet head are both riveted inside the large diameter section, thereby achieving a comprehensive interference fit between the connection section and the hole structure, that is, the rivet head structure inside the large diameter section (including the part with expanded diameter and deformation) has an interference fit with the large diameter section, and the rest of the connection section has an interference fit with the small diameter section, thereby comprehensively improving the contact area between the connection section and the inner wall of the outer plate hole structure, and maximizing the contact area, effectively avoiding the problem of rapid fatigue fracture or wear failure caused by stress concentration in the outer plate hole structure. Figure 4 As shown in a, the riveted structure before improvement only achieved interference fit at 1 / 3 of the connecting section, and the rivet head was in contact with the surface of the outer plate, and could not exert force on the hole structure. Therefore, the contact area between the connecting section and the hole structure after improvement was increased by at least 3 times.

[0034] The hole structure of the present invention is formed by die stamping, and the rivet head block is provided with an inwardly concave spherical groove, so that the end of the pin shaft is riveted to form a spherical structure 15, so that the pin shaft is subjected to more uniform force when the riveting head is riveted, and the connection structure between the pin shaft and the hole structure is more stable.

Claims

1. A riveting structure for a saw chain for logging, characterized by: The riveted structure includes a pin and an outer plate component riveted together with the pin, the outer plate component is provided with a hole structure for interference fit with the pin, the hole structure is a countersunk hole, the inner wall side profile of the large diameter section of the countersunk hole is an arc-shaped structure expanding radially outward, and the small diameter section passes through the inner surface of the outer plate component; the pin includes an annular boss located in the middle and formed by diameter expansion, the two ends of the annular boss constitute a coaxially arranged connecting section, the connecting section passes through the small diameter section, the end of the connecting section is filled in the large diameter section by a riveting process, after riveting, the top edge of the connecting section is flush with the outer surface of the outer plate, the top of the connecting section is an upwardly protruding spherical structure, the connecting section has an interference fit with the small diameter section, and the end of the connecting section has an interference fit with the large diameter section.

2. A riveting structure for a saw chain for logging as claimed in claim 1, characterized in that: The height of the large diameter section is 1 / 3 of the thickness of the outer plate.

3. The riveting structure of a saw chain for logging as claimed in claim 1, characterized in that: The portion where the annular boss is connected to the root of the connecting section is provided with a first chamfered corner structure, and the lower end of the small diameter section is provided with a second chamfered corner structure. After riveting, the first chamfered corner structure and the second chamfered corner structure are closely matched.

4. The riveting structure of a saw chain for logging as claimed in claim 1, characterized in that: The outer plate comprises a left blade plate, a right blade plate and a connecting plate for assembling a saw chain, and the left blade plate, the right guide plate and the connecting plate are respectively provided with two hole structures for assembling a pin shaft.

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