Ratchet wrench and preparation method

Abstract

The invention discloses a ratchet wrench and a preparation method. Relates to a wrench tool. Comprising a wrench body, a ratchet wheel hole is formed in the end of the wrench body, and a semicircular key groove communicated with the ratchet wheel hole is formed in the side of the ratchet wheel hole; a first semicircular groove and a second semicircular groove which are connected are formed in the semicircular key groove; the distance straight line from the circle center of the first semicircular groove to the circle center of the ratchet wheel hole is set as L1, the distance straight line from the circle center of the second semicircular groove to the circle center of the ratchet wheel hole is set as L2, L1 is equal to L2, the included angle between L1 and L2 is T, and T is equal to 360 / ratchet wheel tooth number / 2; the radius of the first semicircular groove is equal to that of the second semicircular groove; the ratchet wheel is rotatably limited in the ratchet wheel hole; the spring seat is matched with the semicircular key groove and arranged on the smooth side of the semicircular key groove; the spring seat is provided with a pair of positioning holes; and the other pawl is meshed with the ratchet wheel. Therefore, the effect that the two pawl teeth and the ratchet teeth are staggered and meshed is achieved.

Description

Technical Field

[0001] The invention relates to a wrench tool, and in particular to a ratchet wrench with improved structure and a design improvement of a preparation method. Background Art

[0002] The development of wrench tools has reached an extremely mature stage. Common types of wrenches include: ratchet wrenches, open-end wrenches, etc. Ratchet wrenches have the advantages of simple and durable structure. They mainly include a ratchet set in the drive hole and a ratchet that cooperates with the outer circumference of the ratchet. Since the number of ratchets is limited by strength issues, the number of ratchet teeth is generally limited to between 72 and 90 teeth. If more teeth are added, the ratchet teeth will be too fine to withstand the transmission of driving force, resulting in structural damage. Therefore, the angle of the replaceable teeth is about 5 degrees or 4 degrees, which cannot be further reduced. This results in the ratchet wrench being unusable under limited working conditions, such as working conditions with a tooth change angle of less than 5 degrees or 4 degrees. If a smaller angle tooth change working state is to be achieved, the teeth of the ratchet and the pawl need to be made finer, which will lead to a reduction in the torque and life of the wrench.

[0003] For this reason, the industry has developed a double-detent detent device, which mainly sets a driving hole for ratchet accommodation in the wrench body, and sets two detent grooves on both sides of the driving hole, and sets two sets of detent devices in the two detent grooves respectively, each detent device includes a detent and a reset member, and cooperates with the ratchet latch in different timings to achieve the purpose of doubling the number of teeth, so that the changeable tooth angle is reduced to half, in order to cope with the working environment where only a small angle can be driven to change teeth. However, the above-mentioned wrench structure must have two detent grooves in the body, which will increase the construction process. In addition, the reset member of each detent device presses against the detent at one end, and presses against the inner wall surface of the detent groove in an arc shape at the other end. The inner wall surface is in an arc shape that gradually becomes shallow. Due to the elastic top force, the reset member will naturally move to the shallower part of the detent groove, and even get stuck in the gap between the detent groove and the ratchet, causing the ratchet to get stuck, so there is a need for improvement. Summary of the invention

[0004] In view of the above problems, the present invention provides a ratchet wrench and a preparation method thereof, which can reduce the tooth change angle without affecting the torque and service life of the wrench, double the number of working teeth, and further improve the stability and scenarios of use.

[0005] The technical solution of the present invention is: A ratchet wrench, comprising: The wrench body has a ratchet hole at the end, and a semicircular keyway connected to the ratchet hole is provided on the side of the ratchet hole; a first semicircular groove and a second semicircular groove connected to each other are provided in the semicircular keyway; the distance straight line from the center of the first semicircular groove to the center of the ratchet hole is L1, and the distance straight line from the center of the second semicircular groove to the center of the ratchet hole is L2, L1=L2, the angle between L1 and L2 is T, T=360 / number of ratchet teeth / 2; the radius of the first semicircular groove is equal to that of the second semicircular groove; A ratchet wheel, rotatably limited in the ratchet hole; A spring seat is adapted to the semicircular keyway and is arranged on the smooth side of the semicircular keyway; a pair of positioning holes is provided on the spring seat; A pair of ratchet pawls are provided, located in the corresponding first semicircular groove and second semicircular groove, and adapted to the ratchet wheel; A pair of springs are provided, one end of which is connected to the corresponding pawl, and the other end of which is connected to the corresponding positioning hole.

[0006] Specifically, the ratchet is limited in the ratchet hole by a retaining spring.

[0007] Specifically, the ratchet has 72 teeth, and the angle of each tooth is 5 degrees, so T=2.5 degrees.

[0008] Specifically, the ratchet has 90 teeth, and the angle of each tooth is 4 degrees, so T=2 degrees.

[0009] Specifically, a wrench opening is provided at the end of the wrench body.

[0010] Specifically, the thickness of the first semicircular groove is equal to the thickness of the second semicircular groove.

[0011] A method for preparing a ratchet wrench comprises the following steps: Step 1: Cut the bar into set lengths and heat it to 900°C~1100°C; Step 2, forging the bar into a wrench blank shape; Step 3, annealing the blank to HRC: 8°-15° in an annealing furnace; Step 4: Processing the ratchet hole, the first and second semicircular keyways and the circlip groove; The first and second semicircular keyway processing steps include: Take the center of the ratchet hole as the reference, and then Figure 2 direction is the reference direction), the center of the first semicircular groove is set, the distance from the center of the first semicircular groove to the center of the ratchet hole is L1, the radius of the first semicircular groove is R1, and the semicircular groove is machined; the semicircular groove is machined using a first semicircular keyway cutter whose thickness is equal to the sum of the thickness of the first semicircular groove and the second semicircular groove; The line connecting the center of the ratchet hole and the center of the first semicircular groove is rotated by T° with the center of the ratchet hole as the rotation point, that is, the angle between the centers of the two semicircular grooves and the center of the ratchet hole is T°; the second semicircular groove is processed by a second semicircular keyway cutter having a thickness equal to that of the second semicircular groove, and the semicircular groove is divided into a first semicircular groove and a second semicircular groove; T=360 / number of ratchet teeth / 2; In this case, the distance from the center of the second semicircular groove to the center of the ratchet hole is L2, and the radius of the second semicircular groove is R2; L1=L2, R1=R2; the second semicircular keyway is machined; Step 5: Assemble the pawl, spring, spring seat, ratchet and retaining ring.

[0012] Specifically, in step 1, a bar cutting machine cuts a round bar made of 40CRV into required lengths, and then heats the round bar to 900°C~1100°C in a medium frequency furnace.

[0013] Specifically, in step 4, after the first and second semicircular grooves are processed, the periphery of the wrench is polished with an abrasive belt to remove the oxide scale and pitting formed on the surface of the wrench during hot forging, and the surface of the wrench is polished smooth.

[0014] Specifically, after the surface is polished and smooth, the polished wrench body is heat treated in a mesh belt quenching furnace, and the hardness requirement is HRC: 38°~46°.

[0015] The present invention adopts a double ratchet and double semicircular groove structural design; the two semicircular grooves have the same size and different positions, and the two ratchet pawls are the same. The semicircular grooves are staggered at an angle so that the two ratchet pawls are staggered and matched with the ratchet. This structure can double the number of working teeth of the ratchet wrench and reduce the tooth change angle by half, so it can be used in a smaller space. At the same time, this structural design does not change the density of the teeth, and has no effect on the torque and service life of the wrench while reducing the tooth change angle.

[0016] The two pawls fit with the corresponding semicircular grooves under the action of the spring. Since the two semicircular grooves are staggered by an angle of half a tooth, when one of the pawls is engaged with the ratchet, the tip of the other pawl contacts the tip of the ratchet. The ratchet, the engaged pawl and the wrench are locked in one direction. At this time, the screw can be turned in the opposite direction with a wrench. When the wrench rotates the ratchet in the opposite direction by an angle of half a tooth, the pawl originally engaged with the ratchet separates from the ratchet under the retraction function of the spring, and the other pawl engages with the ratchet. This achieves the effect of staggered engagement of the two pawl teeth with the ratchet teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural schematic diagram of the present invention; Figure 2 It is a cross-sectional schematic diagram of the ratchet hole side; Figure 3 It is a schematic diagram of the three-dimensional structure of the first and second semicircular grooves; Figure 4 It is a schematic diagram of the structure of the pawl connection state; Figure 5 It is a schematic diagram of the three-dimensional structure of step two; Figure 6 It is a schematic diagram of the three-dimensional structure of step three; Figure 7 It is a schematic diagram of the three-dimensional structure of step four; Figure 8 It is a schematic diagram of the three-dimensional structure of the opening finishing; Fig. 9 It is a schematic diagram of the three-dimensional structure of step five; In the figure, 100 is the lever body, 110 is the ratchet hole, 120 is the opening, 200 is the ratchet, 300 is the pawl, 400 is the spring, 500 is the spring seat, 600 is the semicircular keyway, 610 is the first semicircular groove, and 620 is the second semicircular groove. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] Reference below Figure 1-9 describe the invention; A ratchet wrench 200, comprising: A wrench body 100 is provided with a ratchet hole 110 at one end and a wrench opening at the other end, and a semicircular keyway 600 connected to the ratchet hole 110 is provided on the side thereof; a first semicircular groove 610 and a second semicircular groove 620 connected to each other are provided in the semicircular keyway 600; a straight line from the center of the first semicircular groove 610 to the center of the ratchet hole 110 is L1, and a straight line from the center of the second semicircular groove 620 to the center of the ratchet hole 110 is L2, L1=L2, and an angle between L1 and L2 is T, T=360 / number of ratchet teeth / 2; the radii of the first semicircular groove 610 and the second semicircular groove 620 are equal; Two types of grooves are processed by two types of semicircular keyway cutters. The thickness of the first semicircular keyway cutter is equal to the sum of the thicknesses of the two semicircular grooves, and is used to process the semicircular keyway 600. The thickness of the second semicircular keyway cutter is equal to the thickness of the semicircular groove, that is, the first semicircular groove 610 and the second semicircular groove 620 are processed in sequence.

[0022] In this case, the thickness of the first semicircular groove 610 is equal to the thickness of the second semicircular groove 620 .

[0023] The ratchet 200 is rotatably limited in the ratchet hole 110 by a retaining spring; Preferably, the ratchet 200 has 72 teeth, and the angle of each tooth is 5 degrees, so T=2.5 degrees.

[0024] The ratchet 200 has 90 teeth, and the angle of each tooth is 4 degrees, so T=2 degrees.

[0025] The actuating mechanism comprises: The spring seat 500 is adapted to the semicircular keyway 600 and is arranged on the smooth side of the semicircular keyway 600. The second semicircular groove 620 is offset and rotated to form a step with the first semicircular groove 610 on the other side. A pair of positioning holes are provided on the spring seat 500. A pair of ratchet pawls 300 are provided, respectively located in the corresponding first semicircular groove 610 and second semicircular groove 620, and adapted to the ratchet wheel 200; A pair of springs 400 are provided, one end of which is connected to the corresponding pawls 300, and the other end of which is connected to the corresponding positioning holes.

[0026] A method for preparing a ratchet wrench comprises the following steps: Step 1: Cut the bar into set lengths and heat it to 900°C~1100°C; Specifically, the bar cutting machine cuts the round bar made of 40CRV into the required length, and then heats it to 900℃~1100℃ in a medium frequency furnace.

[0027] Step 2, forging the bar into a wrench blank shape; Specifically, Figure 5As shown, the heated bar is passed through a die on a 400-ton screw press and forged into the shape of a wrench blank.

[0028] like Figure 6 As shown, the forged wrench blank is cut off from the surrounding excess flash using a trimming die; Step 3: Since the hardness of 40CRV steel after heating and cooling is >HRC: 20°, it is not conducive to subsequent machining, so the blank needs to be annealed to HRC: 8°-15° in a continuous mesh belt annealing furnace; Step 4: punching the opening 120; like Figure 7 As shown, the annealed wrench is punched out with a special fixture and punch on a 100-ton punch press to form an opening 120. Since the rough punching process cannot meet the dimensional accuracy and surface finish requirements of this product, a processing allowance must be left when punching the opening 120; like Figure 8 As shown, the wrench with the punched opening 120 is processed to the required size on a hydraulic broaching machine using a special fixture and a corresponding push knife; Step 5: Processing the ratchet hole 110, the semicircular keyway 600 and the retaining ring groove; like Fig. 9 As shown, the other end of the wrench is fixed on the machining center with a special fixture, the ratchet hole 110 is machined with an end mill, the semicircular keyway is machined with a semicircular keyway cutter, and the retaining ring groove is machined with a T-type cutter; The semicircular keyway 600 includes a first semicircular groove 610 and a second semicircular groove 620; The first and second semicircular keyway processing steps include: Take the center of the ratchet hole 110 as the reference, vertically downward (with Figure 2 direction as a reference direction), the center of the first semicircular groove 610 is set, the distance from the center of the first semicircular groove 610 to the center of the ratchet hole 110 is L1, the radius of the first semicircular groove 610 is R1, and the semicircular keyway 600 is machined; the semicircular keyway 600 is machined using a first semicircular keyway cutter having a thickness equal to the sum of the thicknesses of the first semicircular groove 610 and the second semicircular groove 620; The line connecting the center of the ratchet hole 110 and the center of the first semicircular groove 610 is rotated by T° with the center of the ratchet hole 110 as the rotation point, that is, the angle between the centers of the two semicircular grooves and the center of the ratchet hole 110 is T°; the second semicircular groove 620 is machined by a second semicircular keyway cutter having a thickness equal to that of the second semicircular groove 620, and the semicircular grooves are divided into the first semicircular groove 610 and the second semicircular groove 620; T=360 / number of ratchet teeth / 2; In this case, the distance from the center of the second semicircular groove 620 to the center of the ratchet hole 110 is L2, and the radius of the second semicircular groove 620 is R2; L1=L2, R1=R2; the second semicircular keyway 620 is machined; L1=R1*(0.8±0.1) R1=D*(0.4±0.05), D is the ratchet hole diameter; For example, the ratchet 200 has 72 teeth, and the angle of each tooth is 5 degrees, then T = 360 / 72 / 2 = 2.5; The ratchet 200 has 90 teeth, and the angle of each tooth is 4 degrees, so T=360 / 90 / 2=2; Assume that the distance from the center of the second semicircular groove 620 to the center of the ratchet hole 110 is L2, and the radius of the second semicircular groove 620 is R2; L1=L2, R1=R2; After the first and second semicircular grooves are processed, the periphery of the wrench is polished with an abrasive belt to remove the oxide scale and pitting formed on the surface of the wrench during hot forging, and the surface of the wrench is polished smooth; The polished wrench body 100 is heat treated in a mesh belt quenching furnace, and the hardness requirement is HRC: 38°~46°; the wrench body 100 after heat treatment is then chemically polished (high-aluminum porcelain abrasive, cutting agent and wrench chemical reaction) to remove the texture on the surface of the polished wrench and the surface decarburization layer after heat treatment by high-frequency vibration and chemical reaction; the surface of the wrench body 100 is chrome plated Step six, assembling the pawl 300, the spring 400, the spring seat 500, the ratchet and the retaining spring.

[0029] The material of the retaining ring is 65mu; the main production process is to flatten the round 65MU steel wire and then heat treat it.

[0030] The material of ratchet 200 is 50BV30, and the main processing technology is: 1. Use cold heading technology to process the inner plum blossom hole. 2. Use CNC lathe to process the retaining spring groove and step and cut them; 3. The tooth shape of the outer ring is punched by a punching machine and a punching die. 4. Heat treatment, hardness requirement HRC: 38°~46°; 5. The surface is phosphating or blackening treated.

[0031] The spring seat 500 is made of plastic PP, and the processing technology is mold injection molding.

[0032] The material of spring 400 is 65mu.

[0033] The material of the ratchet is Fe8Ni, and the processing technology adopts powder metallurgy process to press and sinter. Its density requirement is: ≥7.6g / cm min, and the hardness after heat treatment is HRC: 43°-48°.

[0034] In summary, the radii of the two semicircular grooves in this case are equal, the distances between the centers of the semicircular grooves and the center of the ratchet hole 110 are equal, and the angle T between the centers of the two semicircular grooves and the center of the ratchet hole 110 is 360 / number of ratchet teeth / 2. A double pawl and double semicircular groove structure is adopted; the staggered angle distance of the two semicircular grooves is used to make the two pawls staggered and match the ratchet. This structure can double the number of working teeth of the ratchet wrench and reduce the tooth change angle by half, so it can be used in a smaller space. At the same time, the structure of this case reduces the tooth change angle by matching the staggered peaks of the pawls with the ratchet, without changing the density of the teeth, so while reducing the tooth change angle, it does not affect the torque and service life of the wrench.

[0035] Regarding the contents disclosed in this case, there are a few points that need to be explained: 1) The drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case, and other structures can refer to the usual designs; 2) In the absence of conflict, the embodiments and features in the embodiments disclosed in this case can be combined with each other to obtain new embodiments; The above are only specific implementation methods disclosed in this case, but the protection scope of the present disclosure is not limited thereto. The protection scope disclosed in this case should be based on the protection scope of the claims.

Claims

1. A ratchet wrench, characterized in that: include: The wrench body has a ratchet hole at the end, and a semicircular keyway connected to the ratchet hole is provided on the side of the ratchet hole; a first semicircular groove and a second semicircular groove connected to each other are provided in the semicircular keyway; the distance straight line from the center of the first semicircular groove to the center of the ratchet hole is L1, and the distance straight line from the center of the second semicircular groove to the center of the ratchet hole is L2, L1=L2, the angle between L1 and L2 is T, T=360 / number of ratchet teeth / 2; the radius of the first semicircular groove is equal to that of the second semicircular groove; A ratchet wheel, rotatably limited in the ratchet hole; A spring seat is adapted to the semicircular keyway and is arranged on the smooth side of the semicircular keyway; a pair of positioning holes is provided on the spring seat; A pair of ratchet pawls are provided, located in the corresponding first semicircular groove and second semicircular groove, and adapted to the ratchet wheel; A pair of springs are provided, one end of which is connected to the corresponding pawl, and the other end of which is connected to the corresponding positioning hole.

2. A ratchet wrench according to claim 1, characterized in that: The ratchet is limited in the ratchet hole by a clamping spring.

3. A ratchet wrench according to claim 1 or 2, characterized in that: The ratchet has 72 teeth, and the angle of each tooth is 5 degrees, so T=2.5 degrees.

4. A ratchet wrench according to claim 1 or 2, characterized in that: The ratchet has 90 teeth, and the angle of each tooth is 4 degrees, so T=2 degrees.

5. A ratchet wrench according to claim 1, characterized in that: The end of the wrench body is provided with a wrench opening.

6. A ratchet wrench according to claim 1, characterized in that: The thickness of the first semicircular groove is equal to the thickness of the second semicircular groove.

7. A method for preparing a ratchet wrench, the ratchet wrench according to claim 1, characterized in that: The following steps are involved: Step 1: Cut the bar into set lengths and heat it to 900°C~1100°C; Step 2, forging the bar into a wrench blank shape; Step 3: anneal the blank to HRC: 8°-15° (material: 40CRV) through an annealing furnace; Step 4: Processing the ratchet hole, the first and second semicircular keyways and the circlip groove; The first and second semicircular keyway processing steps include: Taking the center of the ratchet hole as a reference, the center of the first semicircular groove is set vertically downward, the distance between the center of the first semicircular groove and the center of the ratchet hole is L1, the radius of the first semicircular groove is R1, and the semicircular groove is machined; the semicircular groove is machined using a first semicircular keyway cutter having a thickness equal to the sum of the thickness of the first semicircular groove and the second semicircular groove; The line connecting the center of the ratchet hole and the center of the first semicircular groove is rotated by T° with the center of the ratchet hole as the rotation point, that is, the angle between the centers of the two semicircular grooves and the center of the ratchet hole is T°; the second semicircular groove is processed by a second semicircular keyway cutter having a thickness equal to that of the second semicircular groove, and the semicircular groove is divided into a first semicircular groove and a second semicircular groove; T=360 / number of ratchet teeth / 2; Step 5: Assemble the pawl, spring, spring seat, ratchet and retaining ring.

8. The method for preparing a ratchet wrench according to claim 7, characterized in that: In step 1, the bar cutting machine cuts the round bar made of 40CRV into the required length, and then heats it to 900℃~1100℃ in a medium frequency furnace.

9. The method for preparing a ratchet wrench according to claim 7, characterized in that: In step 4, after the first and second semicircular grooves are processed, the periphery of the wrench is polished with an abrasive belt to remove the oxide scale and pitting formed on the surface of the wrench during hot forging, and the surface of the wrench is polished smooth.

10. A method for preparing a ratchet wrench according to claim 9, characterized in that: After the surface is polished and smooth, the polished wrench body is heat treated in a mesh belt quenching furnace, and the hardness requirement is HRC: 38°~46°.

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