Ratchet wrench capable of reducing tooth changing angle

Abstract

The utility model discloses a ratchet wrench capable of reducing a tooth changing angle and relates to a wrench tool. Comprising a wrench body, a ratchet hole is formed in the end of the wrench body, and a semicircular key groove communicated with the ratchet hole is formed in the side of the ratchet 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, the included angle between L1 and L2 is T, and T = 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 is arranged in the semicircular key groove; the spring seat is provided with a pair of positioning holes; according to the structural design, the density of the teeth is not changed, and the torque and the service life of the wrench are not influenced while the tooth changing angle is reduced.

Description

Technical Field

[0001] The utility model relates to a wrench tool, in particular to a structural improvement of a ratchet wrench for reducing the tooth-changing angle and a design improvement of a preparation method. Background Technique

[0002] Wrench tools have developed to an extremely mature stage. Common types of wrenches include ratchet wrenches, open-end wrenches, etc. Ratchet wrenches have the advantages of simple structure and durability. They mainly include a ratchet arranged in a driving hole and ratchet teeth that cooperate with the outer peripheral surface of the ratchet for braking. Due to the limitation of the number of ratchet teeth by strength problems, the current number of ratchet teeth is generally limited between 72 teeth and 90 teeth. If more teeth are added, the ratchet teeth will be too thin to withstand the transmission of driving force, resulting in structural damage. Therefore, the tooth-changing angle that can be replaced is about 5 degrees or 4 degrees and cannot be further reduced. This leads to the situation that in a working environment with limited space, such as a working state with a tooth-changing angle less than 5 degrees or 4 degrees, this ratchet wrench cannot be used. If a smaller-angle tooth-changing 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 service life of the wrench.

[0003] Therefore, a braking device with double pawls has been developed in the industry. The main body of the wrench is provided with a driving hole for accommodating the ratchet, and two braking grooves are arranged on both sides of the driving hole. Two groups of braking devices are respectively arranged in the two braking grooves. Each braking device includes a pawl and a reset member, and they cooperate with the ratchet for latching in different time sequences, so as to achieve the purpose of doubling the number of teeth for latching, reducing the tooth-changing angle to half, and adapting to the working environment where only small-angle driving tooth-changing is required. However, the above wrench structure must open two braking grooves on the main body, which will increase the construction process. In addition, one end of the reset member of each braking device abuts against the pawl, and the other end abuts against the inner wall surface of the braking groove in an arc shape. The inner wall surface is in a gradually shallower arc shape. Due to the elastic top force, the reset member will naturally move towards the shallower part of the braking groove and even get stuck in the gap between the braking groove and the ratchet, resulting in the ratchet being stuck, so there is a need for improvement. Content of the Utility Model

[0004] The utility model aims at the above problems and provides a ratchet wrench for reducing the tooth-changing angle, which has no influence on the torque and service life of the wrench while reducing the tooth-changing angle, doubles the number of working teeth, and further improves the use stability and scenarios.

[0005] The technical solution of the utility model is as follows:

[0006] A ratchet wrench for reducing the tooth-changing angle, comprising:

[0007] The wrench body has a ratchet hole at its end, and a semi-circular keyway communicating with the side of the ratchet hole; a first semi-circular groove and a second semi-circular groove are connected in the semi-circular keyway; let the straight line distance from the center of the first semi-circular groove to the center of the ratchet hole be L1, and the straight line distance from the center of the second semi-circular groove to the center of the ratchet hole be L2, and the included angle between L1 and L2 is T, T = 360 / number of ratchet teeth / 2; the radii of the first semi-circular groove and the second semi-circular groove are equal;

[0008] The ratchet can be rotatably limited in the ratchet hole;

[0009] The spring seat is adapted to the semi-circular keyway and is arranged in the semi-circular keyway; a pair of positioning holes are provided on the spring seat;

[0010] There are a pair of pawls located in the corresponding first semi-circular groove and second semi-circular groove and adapted to the ratchet;

[0011] There are a pair of springs, one end of which is connected to the corresponding pawl and the other end is connected to the corresponding positioning hole.

[0012] Specifically, the ratchet is limited in the ratchet hole by a circlip.

[0013] Specifically, the ratchet has 72 teeth and each tooth angle is 5 degrees, then T = 2.5 degrees.

[0014] Specifically, the ratchet has 90 teeth and each tooth angle is 4 degrees, then T = 2 degrees.

[0015] Specifically, the end of the wrench body is provided with a wrench opening.

[0016] Specifically, the thickness of the first semi-circular groove is equal to the thickness of the second semi-circular groove.

[0017] The utility model adopts a double-pawl and double-semi-circular groove structure design; the two semi-circular grooves have the same size but different positions, and the two pawls are the same. The two pawls are staggered by an angular distance through the semi-circular grooves so that the two pawls are staggered peaks and coincide with the ratchet. This structure can double the working number of teeth of the ratchet wrench and reduce the tooth-changing angle by half, so it can be used in a narrower space. At the same time, this structural design does not change the tooth density, and has no influence on the torque and service life of the wrench while reducing the tooth-changing angle.

[0018] Under the action of the spring, the two pawls are respectively in contact with the corresponding semi-circular grooves. Since the two semi-circular grooves are staggered by an angle T of half a tooth, when one pawl meshes with the ratchet wheel, the tooth tip of the other pawl contacts the tooth tip of the ratchet wheel. The ratchet wheel, the engaged pawl and the wrench body form a directional lock. At this time, the wrench can be used to turn the screw in the opposite direction. When the wrench rotates the ratchet wheel by an angle of half a tooth in the opposite direction, under the retraction function of the spring, the pawl originally engaged with the ratchet wheel separates from the ratchet wheel, and the other pawl meshes with the ratchet wheel. To achieve the effect that the teeth of the two pawls are staggered from the teeth of the ratchet wheel. Description of the Drawings

[0019] Figure 1 is a three-dimensional structural schematic diagram of the present utility model;

[0020] Figure 2 is a schematic cross-sectional view on the side of the ratchet hole;

[0021] Figure 3 is a three-dimensional structural schematic diagram of the first and second semi-circular grooves;

[0022] Figure 4 is a schematic structural diagram of the connection state of the pawl;

[0023] Figure 5 is a three-dimensional structural schematic diagram of step two;

[0024] Figure 6 is a three-dimensional structural schematic diagram of step three;

[0025] Figure 7 is a three-dimensional structural schematic diagram of step four;

[0026] Figure 8 is a three-dimensional structural schematic diagram of the finish machining of the opening;

[0027] Figure 9 is a three-dimensional structural schematic diagram of step five;

[0028] In the figure, 100 is the wrench body, 110 is the ratchet hole, 120 is the opening, 200 is the ratchet wheel, 300 is the pawl, 400 is the spring, 500 is the spring seat, 600 is the semi-circular keyway, 610 is the first semi-circular groove, and 620 is the second semi-circular groove. Detailed Embodiment

[0029] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model.

[0030] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0031] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] The following refers to Figures 1-9 describe the present utility model;

[0033] A ratchet 200 wrench, comprising:

[0034] A wrench body 100, one end of which is provided with a ratchet hole 110, the other end is provided with a wrench opening, and a semi-circular keyway 600 communicating with the side of the ratchet hole 110; a first semi-circular groove 610 and a second semi-circular groove 620 are connected in the semi-circular keyway 600; let the straight line distance from the center of the first semi-circular groove 610 to the center of the ratchet hole 110 be L1, and the straight line distance from the center of the second semi-circular groove 620 to the center of the ratchet hole 110 be L2, and the included angle between L1 and L2 is T, T = 360 / number of ratchet teeth / 2; the radii of the first semi-circular groove 610 and the second semi-circular groove 620 are equal;

[0035] Two types of grooves are machined by two types of semi-circular keyway cutters. The thickness of the first semi-circular keyway cutter is equal to the sum of the thicknesses of the two semi-circular grooves, and it is used to machine the semi-circular keyway 600. The thickness of the second semi-circular keyway cutter is equal to the thickness of the semi-circular groove, that is, the first semi-circular groove 610 and the second semi-circular groove 620 are machined in sequence.

[0036] In this case, the thickness of the first semi-circular groove 610 is equal to the thickness of the second semi-circular groove 620.

[0037] A ratchet 200, which is rotatably limited in the ratchet hole 110 through a snap ring;

[0038] Preferably, the ratchet 200 has 72 teeth, and the angle of each tooth is 5 degrees, then T = 2.5 degrees.

[0039] The ratchet wheel 200 has 90 teeth, and the angle of each tooth is 4 degrees, so T = 2 degrees.

[0040] The braking mechanism includes:

[0041] A spring seat 500, which is adapted to the semi-circular keyway 600 and is arranged on the smooth side of the semi-circular keyway 600. A step is formed between the other side where the second semi-circular groove 620 is offset and rotated and the first semi-circular groove 610; a pair of positioning holes are provided on the spring seat 500;

[0042] Two pawls 300, which are respectively located in the corresponding first semi-circular groove 610 and second semi-circular groove 620 and are adapted to the ratchet wheel 200;

[0043] Two springs 400, one end of each spring is respectively connected to the corresponding pawl 300, and the other end of each spring is respectively connected to the corresponding positioning hole.

[0044] A preparation method for a ratchet wrench for reducing the tooth-changing angle includes the following steps:

[0045] Step 1: Cut the bar stock into a set length and heat it to 900 °C - 1100 °C;

[0046] Specifically, a bar stock cutting machine cuts a round bar stock made of 40CRV into the required length, and then heats it to 900 °C - 1100 °C with an intermediate frequency furnace.

[0047] Step 2: Forge the bar stock into the shape of a wrench blank;

[0048] Specifically, as Figure 5 shown, the heated bar stock is forged into the shape of a wrench blank through a die on a 400-ton screw press.

[0049] As Figure 6 shown, the excess flash around the forged wrench blank is removed by a trimming die;

[0050] Step 3: Since the hardness of the steel material of 40CRV is > HRC: 20° after heating and cooling, which is not conducive to subsequent machining, the blank needs to be annealed to HRC: 8° - 15° through a continuous mesh belt annealing furnace;

[0051] Step 4: Blanking and punching for the opening 120;

[0052] As Figure 7 shown, the annealed wrench is punched with a special fixture and punch on a 100-ton punch press to punch out the opening 120. Since the rough punching process cannot meet the dimensional accuracy and surface finish requirements of this product, machining allowance needs to be left when punching the opening 120;

[0053] AsFigure 8 As shown, use a special fixture and a corresponding broaching tool to process the opening 120 of the wrench to the required size on a hydraulic broaching machine;

[0054] Step Five: Process the ratchet hole 110, the semi-circular keyway 600, and the snap ring groove;

[0055] As Figure 9 shown, fix the other end of the wrench on the machining center with a special fixture, use an end mill to machine the ratchet hole 110, use a semi-circular keyway cutter to machine the semi-circular keyway, and then use a T-slot cutter to machine the snap ring groove;

[0056] The semi-circular keyway 600 includes a first semi-circular groove 610 and a second semi-circular groove 620;

[0057] The processing steps for the first and second semi-circular keyways include:

[0058] Taking the center of the ratchet hole 110 as the reference, set the center of the first semi-circular groove 610 vertically downward (taking the Figure 2 direction as the reference direction). The distance from the center of the first semi-circular groove 610 to the center of the ratchet hole 110 is L1, and the radius of the first semi-circular groove 610 is R1. Machine the semi-circular keyway 600; Use the first semi-circular keyway cutter with a thickness equal to the sum of the thicknesses of the first semi-circular groove 610 and the second semi-circular groove 620 to machine the semi-circular keyway 600;

[0059] Rotate the line connecting the center of the ratchet hole 110 and the center of the first semi-circular groove 610 by T° with the center of the ratchet hole 110 as the rotation point, that is, the angle between the centers of the two semi-circular grooves and the center of the ratchet hole 110 is T°; Use the second semi-circular keyway cutter with a thickness equal to the thickness of the second semi-circular groove 620 to machine the second semi-circular groove 620, and divide the semi-circular groove into the first semi-circular groove 610 and the second semi-circular groove 620;

[0060] T = 360 / number of ratchet teeth / 2;

[0061] In this case, the distance from the center of the second semi-circular groove 620 to the center of the ratchet hole 110 is L2, and the radius of the second semi-circular groove 620 is R2; L1 = L2, R1 = R2; Machine the second semi-circular keyway 620;

[0062] L1 = R1 * (0.8 ± 0.1)

[0063] R1 = D * (0.4 ± 0.05), where D is the diameter of the ratchet hole;

[0064] For example, if the ratchet 200 has 72 teeth and each tooth has an angle of 5 degrees, then T = 360 / 72 / 2 = 2.5;

[0065] If the ratchet 200 has 90 teeth and each tooth has an angle of 4 degrees, then T = 360 / 90 / 2 = 2;

[0066] 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;

[0067] 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;

[0068] The polished wrench body 100 is heat-treated in a mesh belt quenching furnace, with a hardness requirement of 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 lines on the polished wrench surface and the surface decarburization layer after heat treatment through high-frequency vibration and chemical reaction; the surface of the wrench body 100 is chrome-plated

[0069] Step six, assembling the pawl 300, spring 400, spring seat 500, ratchet and retaining ring.

[0070] The material of the retaining ring is 65mu; the main production process is to flatten the round 65MU steel wire into shape and then heat treat it.

[0071] The ratchet 200 is made of 50BV30 and the main processing technology is:

[0072] 1. Use cold heading process to process the inner plum blossom hole.

[0073] 2. Use CNC lathe to process the circlip groove and step and cut;

[0074] 3. The tooth shape of the outer ring is punched by a punching machine and a punching die.

[0075] 4. Heat treatment, hardness requirement HRC: 38°~46°;

[0076] 5. The surface is treated with phosphating or blackening.

[0077] The spring seat 500 is made of plastic PP, and the processing technology is mold injection molding.

[0078] The material of spring 400 is 65mu.

[0079] The pawl is made of Fe8Ni and is processed by powder metallurgy process of pressing and sintering. Its density requirement is: ≥7.6g / cm min, and the hardness after heat treatment is HRC: 43°-48°.

[0080] In summary, in this case, the radii of the two semi-circular grooves are equal, the distances from the centers of the semi-circular grooves to the center of the ratchet hole 110 are equal, and the angle T between the centers of the two semi-circular grooves and the center of the ratchet hole 110 is T = 360 / number of ratchet teeth / 2. A double-ratchet-pawl and double-semi-circular-groove structure is adopted; the staggering angle distance between the two semi-circular grooves is used to make the two ratchet pawls stagger peaks to fit with the ratchet. This structure can double the number of working teeth of the ratchet wrench and reduce the tooth-changing angle by half, so it can be used in a smaller space. At the same time, the structure in this case reduces the tooth-changing angle by making the ratchet pawls stagger peaks to fit with the ratchet, without changing the tooth density, so it has no impact on the torque and service life of the wrench while reducing the tooth-changing angle.

[0081] Regarding the content disclosed in this case, the following points need to be explained:

[0082] 1) The attached drawings of the embodiments disclosed in this case only relate to the structures involved in the disclosed embodiments, and other structures can refer to the general design;

[0083] 2) Without conflict, the disclosed embodiments and the features in the embodiments in this case can be combined with each other to obtain new embodiments;

[0084] The above is only the specific implementation manner disclosed in this case, but the protection scope of this disclosure is not limited thereto. The protection scope disclosed in this case shall be subject to the protection scope of the claims.

Claims

1. A ratchet wrench for reducing the tooth-changing angle, characterized in that Comprising: A wrench body, with a ratchet hole at one end, and a semi-circular keyway communicating with the side of the ratchet hole; the semi-circular keyway includes a connected first semi-circular groove and a second semi-circular groove; let the straight line distance from the center of the first semi-circular groove to the center of the ratchet hole be L1, and the straight line distance from the center of the second semi-circular groove to the center of the ratchet hole be L2, there is a T-degree angle between L1 and L2, T = 360 / number of ratchet teeth / 2; the radii of the first semi-circular groove and the second semi-circular groove are equal; A ratchet, rotatably limited in the ratchet hole; A spring seat, adapted to the semi-circular keyway, arranged in the semi-circular keyway, and provided with a pair of positioning holes; Pawl, there are a pair of them, located in the corresponding first semi-circular groove and second semi-circular groove, and adapted to the ratchet; Springs, there are a pair of them, one end is connected to the corresponding pawl, and the other end is connected to the corresponding positioning hole.

2. The ratchet wrench for reducing the tooth-changing angle according to claim 1, wherein, The ratchet is limited in the ratchet hole by a circlip.

3. The ratchet wrench for reducing the tooth-changing angle according to claim 1 or 2, characterized in that, The ratchet has 72 teeth, and each tooth has an angle of 5 degrees, then T = 2.5 degrees.

4. The ratchet wrench for reducing the tooth-changing angle according to claim 1 or 2, wherein, The ratchet has 90 teeth, and each tooth has an angle of 4 degrees, then T = 2 degrees.

5. The ratchet wrench for reducing the tooth-changing angle according to claim 1, wherein The end of the wrench body is provided with a wrench opening.

6. The ratchet wrench for reducing the tooth-changing angle according to claim 1, characterized in that, The thickness of the first semi-circular groove is equal to the thickness of the second semi-circular groove.

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