A knife seat and processing method thereof

Abstract

The present invention belongs to the technical field of lawn mowers, and particularly relates to a knife seat, comprising a mounting seat die-casted by a powder metallurgy process, wherein a connecting seat is arranged at one end of the mounting seat, and a mounting protrusion and a positioning protrusion for mounting a knife are arranged at the other end of the mounting seat, and a plurality of annular stress grooves are arranged on the mounting seat, and the annular stress grooves respectively surround the outer periphery of the mounting protrusion / positioning protrusion. The purpose of the present invention is to provide a knife seat with a simple structure, convenient production and less internal stress during the production process.

Description

Technical Field

[0001] The invention belongs to the technical field of lawn mowers, in particular to a blade holder. Background Art

[0002] A lawn mower is a common gardening tool. It cuts grass and trees with a high-speed rotating blade. During use, the blade holder where the blade is installed is subjected to great stress. The blade holder is easily damaged after long-term use. In addition, many lawn mower blade holders on the market have unreasonable structures, resulting in large internal stress in the blade holder during the production process. Cracks are prone to occur in the blade holder during the production process, which affects the product's qualification rate and service life. Summary of the invention

[0003] In order to overcome the deficiencies and existing problems in the prior art, the present invention provides a tool holder which has a simple structure, is easy to produce and has low internal stress during the production process.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A tool holder comprises a mounting seat formed by die-casting through a powder metallurgy process, wherein a connecting seat is arranged at one end of the mounting seat, and a mounting protrusion and a positioning protrusion for mounting a tool are arranged at the other end of the mounting seat, and a plurality of annular stress grooves are arranged on the mounting seat, and the annular stress grooves respectively surround the outer periphery of the mounting protrusion / positioning protrusion.

[0006] Preferably, the positioning protrusion is in a strip shape and is arranged around the circumference of the mounting protrusion. The positioning protrusion is inclined relative to the radial direction of the circumference and has the same inclination direction as the blade on the tool.

[0007] Preferably, the mounting seat is provided with two groups of positioning protrusions, and the two groups of positioning protrusions are centrally symmetrically arranged on both sides of the mounting protrusion.

[0008] Preferably, a plurality of grooves are provided on the mounting seat, and mounting protrusions / positioning protrusions extend from the bottom of the grooves to form the annular stress groove.

[0009] Preferably, the cross-section of the annular stress groove is trapezoidal, the inner wall of the annular stress groove is the side wall of the mounting protrusion or the side wall of the positioning protrusion, and the outer wall of the stress groove is an inclined side wall.

[0010] Preferably, a step portion is provided on the outer periphery of the end portion of the positioning protrusion, and the step portion is connected to the end portion of the positioning protrusion via an inclined surface.

[0011] Preferably, a connecting hole is provided in the connecting seat, and an annular stress groove is provided on the outer periphery of the bottom of the connecting hole.

[0012] Preferably, the mounting protrusion and the positioning protrusion are both platforms, and the cross-section of the mounting protrusion gradually decreases as the distance from the mounting seat increases.

[0013] A method for processing a tool holder comprises the following specific steps:

[0014] Step 1: Raw material processing: evenly mix the iron-based powder and auxiliary materials according to the ratio for standby use;

[0015] Step 2, forming, feeding a certain amount of mixed raw material powder into a press, and forming the green body of the tool holder by one-time molding;

[0016] Step 3, sintering, placing the green body into a sintering furnace for high-temperature sintering, the sintering temperature is 800°C-1000°C, and the heat preservation time is 1-3 hours;

[0017] Step 4: Polishing: After the sintered knife seat is cooled, polishing treatment is performed;

[0018] Step 5: Steam treatment: steam treatment is performed on the polished knife holder;

[0019] Step 6: Check the appearance of the tool holder to eliminate any quality problems.

[0020] Step 7: Oil-immersion packaging: immerse the knife holder in oil in a container and then package the knife holder.

[0021] Preferably, the iron-based powder and auxiliary materials are mixed in the following ratios: carbon: 0.8%, copper: 1.2%, nickel: 1.2%, and iron: the remainder.

[0022] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects:

[0023] (1) In the present invention, the stress between the mounting protrusion / positioning protrusion and the mounting seat is reduced by an annular stress groove, so as to avoid cracks on the tool holder due to the large stress between the mounting protrusion / positioning protrusion and the mounting seat during the production process, thereby reducing the scrap rate of the tool holder during the production process. The mounting seat is provided with a plurality of grooves, and the mounting protrusion / positioning protrusion extends from the bottom of the groove to form the annular stress groove, which has a simple structure and is easy to produce, and can effectively reduce the stress between the mounting protrusion / positioning protrusion and the mounting seat; the cross-section of the annular stress groove is trapezoidal, the inner wall of the annular stress groove is the side wall of the mounting protrusion or the side wall of the positioning protrusion, and the outer wall of the stress groove is an inclined side wall, which is conducive to avoiding stress concentration between the side wall of the annular stress groove and the end face of the mounting seat.

[0024] (2) The positioning protrusion described in the present invention is in the shape of a strip and is arranged around the circumference of the mounting protrusion. The positioning protrusion is inclined relative to the radius of the circumference and is arranged in the same direction as the inclination of the blade on the tool. Since most common lawn mowers have inclined blades, the inclined positioning protrusion is conducive to uniform force between the tool and the tool holder, avoiding stress concentration that may cause damage to the positioning protrusion or the tool; two groups of positioning protrusions are arranged on the mounting seat, and the two groups of positioning protrusions are symmetrically arranged on both sides of the mounting protrusion. This structure is conducive to balancing the force between the tool and the tool holder, avoiding uneven force on the positioning protrusion that may cause large local stress on the tool holder; a connecting hole is provided in the connecting seat, and an annular stress groove is provided on the outer periphery of the bottom of the connecting hole, so as to avoid large stress on the outer periphery of the end of the connecting hole during production, which may cause the tool holder to be easily cracked and damaged.

[0025] (3) The outer periphery of the end of the positioning protrusion described in the present invention is provided with a step portion, and the step portion and the end of the positioning protrusion are connected by an inclined surface. This structure is beneficial to reducing the wear of the outer periphery of the end face of the positioning protrusion during use, and is beneficial to extending the service life of the tool holder; the mounting protrusion and the positioning protrusion are both table bodies, and the cross-section of the mounting protrusion gradually decreases as the distance between the mounting protrusion and the mounting seat increases. The structure of the table body facilitates the demoulding of the tool holder during the production process, and facilitates the positioning and installation of the tool and the positioning protrusion.

[0026] (4) The tool holder produced by the process of the present invention has good performance and quality, which can avoid cracking of the tool holder due to stress during the production process and reduce the unqualified rate during the tool holder production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view of the present invention;

[0028] Figure 2 It is a schematic diagram of the installation structure of the tool of the present invention on the tool holder;

[0029] Figure 3 It is a structural schematic diagram of the knife holder in the present invention.

[0030] In the figure: 1-tool holder; 2-tool; 11-mounting seat; 12-connecting seat; 13-mounting protrusion; 14-positioning protrusion; 15-connecting hole; 16-annular stress groove; 17-step portion; 18-inclined surface; 19-reinforcement rib; 21-tool blade. DETAILED DESCRIPTION

[0031] To facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0032] like Figures 1 to 3As shown, a tool holder includes a mounting seat 11 die-casted by a powder metallurgy process, wherein a connecting seat 12 is provided at one end of the mounting seat 11, and reinforcing ribs 19 are provided on both sides of the connecting seat 21, and a mounting protrusion 13 and a positioning protrusion 14 for mounting a tool 2 are provided at the other end of the mounting seat 11, and a plurality of annular stress grooves 16 are provided on the mounting seat 11, and the annular stress grooves 16 are respectively surrounded by the outer periphery of the mounting protrusion 13 / positioning protrusion 14, and the annular stress grooves 16 are formed by integral die-casting for convenient production. In this embodiment, two groups of positioning protrusions 14 are provided on the mounting seat 11, and the two groups of positioning protrusions 14 are centrally symmetrically arranged on both sides of the mounting protrusion 13, and two groups of holes cooperating with the positioning protrusions 14 and one group of holes cooperating with the mounting protrusion 13 are provided on the tool 2.

[0033] The mounting seat 11 is provided with three groups of grooves, and the mounting protrusion 13 and the two groups of positioning protrusions 14 extend from the bottom of the three groups of grooves respectively, and the annular stress groove 16 is formed on the periphery of the positioning protrusion 14 and the mounting protrusion 13. This structure enables the stress groove to be in close contact with the mounting protrusion 13 and the positioning protrusion 14, so as to effectively reduce the stress at the bottom of the positioning protrusion 14 and the mounting protrusion 13.

[0034] The blade 21 on the cutter 2 of the lawn mower on the market is mostly set at an angle. Preferably, the positioning protrusion 14 is in a strip shape and is arranged around the circumference of the mounting protrusion 13. The positioning protrusion 14 is set at an angle relative to the radius of the circumference and has the same inclination direction as the blade 21 on the cutter 2. This structure facilitates the transmission of force between the positioning protrusion 14 and the cutter 2, avoiding the force on the blade 21 and the relative inclination of the positioning protrusion 14, resulting in large local stress on the positioning protrusion 14, which affects the service life of the cutter 2 and the cutter seat 1.

[0035] Preferably, the cross-section of the annular stress groove 16 is trapezoidal, the inner wall of the annular stress groove 16 is the side wall of the mounting protrusion 13 or the side wall of the positioning protrusion 14, and the outer wall of the stress groove is an inclined side wall, which is convenient for demolding and helps to avoid the stress problem between the stress groove and the end face of the mounting seat 11. In this embodiment, a connecting hole 15 is provided in the connecting seat 12, and an annular stress groove 16 is provided on the outer periphery of the bottom of the connecting hole 15.

[0036] The outer periphery of the end of the positioning protrusion 14 is provided with a step portion 17, and the step portion 17 is connected to the end of the positioning protrusion 14 through an inclined surface 18. This structure is beneficial to reducing the wear of the outer periphery of the end surface of the positioning protrusion 14 during use, and is beneficial to extending the service life of the tool holder 1. In this embodiment, the outer peripheries of the ends of the connecting seat 12, the mounting seat 11 and the mounting protrusion 13 are all provided with a step portion 17.

[0037] Preferably, the mounting protrusion 13 and the positioning protrusion 14 are both platforms, and the cross section of the mounting protrusion 13 gradually decreases as the distance from the mounting seat 11 increases. This structure facilitates demoulding of the tool holder 1 and quick installation of the tool 2.

[0038] A method for processing the tool holder of the present invention comprises the following specific steps:

[0039] Step 1: Raw material processing: evenly mix the iron-based powder and auxiliary materials according to the ratio for standby use;

[0040] Step 2, forming, feeding a certain amount of mixed raw material powder into a press, and forming the green body of the tool holder by one-time molding;

[0041] Step 3, sintering, placing the green body into a sintering furnace for high-temperature sintering, the sintering temperature is 800°C-1000°C, and the heat preservation time is 1-3 hours;

[0042] Step 4: Polishing: After the sintered knife seat is cooled, polishing treatment is performed;

[0043] Step 5: Steam treatment: steam treatment is performed on the polished knife holder;

[0044] Step 6: Check the appearance of the tool holder to eliminate any quality problems.

[0045] Step 7: Oil-immersion packaging: immerse the knife holder in oil in a container and then package the knife holder.

[0046] Preferably, the iron-based powder and auxiliary materials are mixed in the following ratios: carbon: 0.8%, copper: 1.2%, nickel: 1.2%, and iron: the remainder.

[0047] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A tool holder, comprising a mounting seat (11) die-casted by a powder metallurgy process, characterized in that: A connecting seat (12) is provided at one end of the mounting seat (11), and a mounting protrusion (13) and a positioning protrusion (14) for mounting a tool (2) are provided at the other end of the mounting seat (11); a plurality of annular stress grooves (16) are provided on the mounting seat (11), and the annular stress grooves (16) respectively surround the outer circumference of the mounting protrusion (13) / positioning protrusion (14); The mounting seat (11) is provided with a plurality of grooves, and the mounting protrusions (13) / positioning protrusions (14) extend from the bottom of the grooves to form the annular stress groove (16); The cross section of the annular stress groove (16) is trapezoidal, the inner wall of the annular stress groove (16) is the side wall of the mounting protrusion (13) or the side wall of the positioning protrusion (14), the outer wall of the annular stress groove (16) is an inclined side wall, and the tool (2) is provided with two groups of holes cooperating with the positioning protrusion (14) and one group of holes cooperating with the mounting protrusion (13).

2. A knife holder according to claim 1, characterized in that: The positioning protrusion (14) is strip-shaped and is arranged around the circumference of the mounting protrusion (13), and the positioning protrusion (14) is arranged inclined relative to the circumferential radius and has the same inclination direction as the blade (21) on the tool (2).

3. A knife holder according to claim 2, characterized in that: Two groups of positioning protrusions (14) are arranged on the mounting seat (11), and the two groups of positioning protrusions (14) are arranged on both sides of the mounting protrusion (13) in a centrally symmetrical manner.

4. A knife holder according to claim 1, 2 or 3, characterized in that: A step portion (17) is provided on the outer periphery of the end portion of the positioning protrusion (14), and the step portion (17) is connected to the end portion of the positioning protrusion (14) via an inclined surface (18).

5. A knife holder according to claim 4, characterized in that: A connection hole (15) is provided in the connection seat (12), and an annular stress groove (16) is provided on the outer periphery of the bottom of the connection hole (15).

6. A knife holder according to claim 1 or 2 or 3 or 5, characterized in that: The mounting protrusion (13) and the positioning protrusion (14) are both platforms, and the cross section of the mounting protrusion (13) gradually decreases as the distance between the mounting protrusion (13) and the mounting seat (11) increases.

7. A method for processing a tool holder, characterized in that: The knife holder is the knife holder according to claim 1, comprising the following specific steps: Step 1: Raw material processing: evenly mix the iron-based powder and auxiliary materials according to the ratio for standby use; Step 2, forming, feeding a certain amount of mixed raw material powder into a press, and forming the green body of the tool holder by one-time molding; Step 3, sintering, placing the green body into a sintering furnace for high-temperature sintering, the sintering temperature is 800°C-1000°C, and the heat preservation time is 1-3 hours; Step 4: Polishing: After the sintered knife seat is cooled, polishing treatment is performed; Step 5: Steam treatment: steam treatment is performed on the polished knife holder; Step 6: Check the appearance of the tool holder to eliminate any quality problems. Step 7: Oil-immersion packaging: immerse the knife holder in oil in a container and then package the knife holder.

8. A method for processing a tool holder according to claim 7, characterized in that: The iron-based powder and auxiliary materials are mixed in the following ratios: carbon: 0.8%, copper: 1.2%; Nickel: 1.2%, Iron: balance.

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