Wrench structure and manufacturing method for the same

Abstract

To provide a wrench structure in which a driver pit is integrally formed from a same material on an end face of a hexagonal shaft body, and which has cost advantage since specific processing means can be eliminated and processing man-hours can be decreased.SOLUTION: In a wrench structure in which a driver pit is integrally formed from the same material at an end of a hexagonal shaft body 3 serving as a wrench, a conical body 4a with a flat apex is so provided on an apical surface of the hexagonal shaft body 3 as to project in a coaxial arrangement, and a concave groove 5 is provided in an external surface from the conical body 4a to the hexagonal shaft body 3. Four concave grooves 5 are provided at equal intervals in a circumferential direction of the hexagonal shaft body 3, whereby the conical body 4a is formed on the driver bit 4 which has a cross shape in a tip view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to a wrench structure that enables a hexagon socket bolt and a wood screw having a cross-shaped engagement groove to be tightened and loosened with a single tool, and to a method for manufacturing the same. [Background technology]

[0002] For example, when fixing a component to a desired part, some systems use a fixing structure that combines a hexagon socket bolt to ensure a certain fixing strength with a wood screw for auxiliary purposes such as preventing rotation. In such cases, two types of tools are required for fixing and removing the component: a hexagon wrench for tightening and loosening the hexagon socket bolt, and a cross head screwdriver for tightening and loosening the wood screw.

[0003] However, when using two types of tools, the hex wrench and the cross screwdriver, as described above, it is necessary to switch tools in the middle of a task, which is inefficient and causes various inconveniences in terms of tool management, purchasing costs, etc. Therefore, in recent years, a wrench structure has been proposed in which a driver bit is provided at the tip of the hex wrench, integrating the two, so that hex socket bolts and wood screws can be tightened and loosened continuously with a single tool without the need to switch tools.

[0004] Conventional wrench structures that integrate a hexagonal wrench and a driver bit include a combined structure in which the hexagonal shaft that forms the hexagonal wrench and the driver bit are manufactured separately and the driver bit is attached to the end of the hexagonal shaft, and a wrench structure in which the driver bit is machined out by cutting the end of the hexagonal shaft, so that the hexagonal wrench and the driver bit are integrated in terms of their metallic structure.

[0005] The former combined wrench structure requires a separate assembly process in addition to the machining process of the hexagonal wrench and driver bit, and in the machining process of the hexagonal wrench, a retaining hole that opens at the end face of the hexagonal shaft and a screw hole on the side are machined in advance, and in the assembly process, the driver bit is inserted into the retaining hole and a set screw is screwed into the screw hole, and the driver bit is fixed to the hexagonal shaft so that its tip is located on the end face of the hexagonal shaft (Patent Document 1).

[0006] The latter one-piece wrench structure is made by cutting a concave surface into the end surface of a hexagonal shaft with a cutting tool, leaving a cone-shaped body at the center of the bottom of the concave surface so as to be coaxial with the hexagonal shaft, and then cutting the cone-shaped body into a cross shape to make a driver bit (Patent Document 2).

[0007] Incidentally, the wrench structure of the former assembled structure has the driver bit separate from the hexagonal shaft, so although it has low strength, it has the advantage that it can be replaced if damaged. However, the problem is that the processing and assembly processes become more complicated as the number of component parts increases, and production takes time and effort, resulting in high costs.

[0008] In contrast, the latter one-piece wrench structure has the driver bit formed metallurgically as a single unit from the same material as the hexagonal shaft, which not only improves the strength of the driver bit but also eliminates the assembly process and allows it to be formed from a single material, making it advantageous in terms of materials and production costs.

[0009] Incidentally, as a specific manufacturing method for obtaining such an integral wrench structure, in addition to the cutting process described above, forging and casting processes can be used. However, such forging and casting processes not only require larger equipment than cutting processes, but also have the problem of high operating costs during use. Therefore, it is more realistic and preferable to manufacture the wrench structure using the generally used cutting process.

[0010] However, in the case of the wrench structure of Patent Document 2, in which the above-mentioned one-piece wrench structure is obtained by cutting, the end face of the hexagonal shaft is machined into a concave surface while leaving a pyramidal body in the center, and further, grooves must be cut in a cross shape at four locations of this pyramidal body to form the driver bit. Since the shape of the concave surface becomes unique by leaving a pyramidal body, it is necessary to develop a dedicated cutting tool for the cutting process, and the control of the cutting tool during cutting becomes complicated, which increases the processing time, leaving room for improvement to reduce the product price. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Utility Model Application Publication No. 62-192875 [Patent Document 2] Japanese Patent Application Publication No. 10-235568 Summary of the Invention [Problem to be solved by the invention]

[0012] Therefore, the object of the present invention is to provide a wrench structure and a manufacturing method thereof, in which a driver bit is integrally formed from the same material on the end face of a hexagonal shaft, and the formation of the bit on the hexagonal shaft can be achieved by a commonly used general cutting process alone, thereby eliminating the need for special processing means and reducing the number of processing steps, thereby making it cost-effective. [Means for solving the problem]

[0013] In order to solve the above problems, the invention of claim 1 has a wrench structure in which a driver bit is integrally formed from the same material at the end of a hexagonal shaft that serves as a wrench, a conical body with a flat top is protruded from the tip face of the hexagonal shaft in a coaxial arrangement, and a groove is provided on the outer surface extending from this conical body to the hexagonal shaft, between the top of the conical body and a position midway axially rearward of the tip face of the hexagonal shaft, with the length direction running along the axial direction of the hexagonal shaft, and four of these grooves are provided at equal intervals around the circumferential direction of the hexagonal shaft, thereby forming the conical body into a driver bit with a cross shape when viewed from the tip.

[0014] The invention of claim 2 is such that the above-mentioned groove has a V-shaped cross-sectional shape, its maximum width is set narrower than the length of one side of the hexagon at the end face of the hexagonal shaft body, and the entire longitudinal length at the bottom of the groove forms a single circular arc.

[0015] The invention of claim 3 is such that, in the arrangement of the grooves in the circumferential direction of the hexagonal shaft, the center line of any one of the grooves in the width direction coincides with one of the corners of the hexagon on the end face of the hexagonal shaft, and the depth direction is arranged along the radial center line connecting the one corner and the axis of the hexagonal shaft, and one length direction of the cross-shaped engagement ridge of the driver bit adjacent to the groove is in a positional relationship of 45° to the radial center line connecting the one corner and the axis of the hexagonal shaft.

[0016] The invention of claim 4 is a manufacturing method of a wrench structure comprising a cutting step of cutting out a conical body with a flat top from the tip surface of a hexagonal shaft that forms a wrench, so that it protrudes in a coaxial arrangement with the hexagonal shaft, and a groove cutting step of cutting four grooves, the length of which runs along the axial direction of the hexagonal shaft, at equally spaced intervals around the hexagonal shaft on the outer surface extending from the conical body to the hexagonal shaft, between the top of the conical body and a position axially inward relative to the end face of the hexagonal shaft.

[0017] Here, the hexagonal shaft body is integrally attached to the tip of a shaft body having a predetermined length so as to have a larger diameter than the shaft body, and the conical body protruding from the tip surface of the hexagonal shaft body is machined integrally from the hexagonal shaft body by cutting the excess length portion set on the tip side of the hexagonal shaft body with a cutting tool by lathe processing.

[0018] In addition, the groove cutting process for turning the conical body into a cross-shaped driver bit is performed by using a milling cutter to cut four grooves at 90° intervals around the periphery of the hexagonal shaft from the top of the conical body to the outer surface of the hexagonal shaft. Effect of the Invention

[0019] According to the wrench structure of this invention, a conical body with a flat top is protruded coaxially from the end face of a hexagonal shaft, and a long groove is provided along the axial direction of the hexagonal shaft on the outer surface extending from the top of the conical body to the hexagonal shaft. Four of the grooves are arranged at equal intervals around the periphery of the hexagonal shaft to form the conical body into a driver bit. This results in a structure in which the formation of the bit for the hexagonal shaft can be manufactured using only general cutting processes that are widely used, and furthermore, by eliminating the need for special processing means and reducing the number of processing steps, it is possible to reduce processing costs.

[0020] Furthermore, in order to form a conical body into a driver bit, the four grooves provided on the hexagonal shaft are positioned so that one of the grooves coincides with one corner of the hexagon on the end face of the hexagonal shaft, the groove width is set narrower than the length of one side of the hexagon, and the length direction of one of the cross-shaped engaging ridges of the driver bit adjacent to the groove is at a 45° angle with the radial center line connecting the one corner and the axis of the hexagonal shaft. This leaves four corners of the hexagon as points of action at the end of the hexagonal shaft, thereby ensuring the strength of the hexagonal shaft as a wrench, and since each of the cross-shaped engaging ridges of the driver bit reaches the four corners, the strength of the driver bit is also ensured. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing the overall shape of a wrench structure according to the present invention; [Diagram 2] FIG. 1 is a front view showing a main part of a wrench structure according to the present invention; [Diagram 3] FIG. 1 is a plan view showing a main part of a wrench structure according to the present invention; [Figure 4] FIG. 1 is an enlarged right side view of a main part of a wrench structure according to the present invention, as viewed from the front end. [Diagram 5] 1 shows a process for manufacturing a wrench structure according to the present invention, in which (a) is a front view of a state in which a cone-shaped body is machined onto the tip surface of a hexagonal shaft, and (b) is a partially cut-away front view of a state in which a groove is machined from the cone-shaped body to the hexagonal shaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0023] As shown in FIG. 1, the wrench structure 1 of the present invention is composed of a hexagonal shaft 3 which serves as a wrench at the end of a shaft 2 having a predetermined length, and a driver bit 4 which is provided on the end surface of the hexagonal shaft 3 and whose small-diameter tip side protrudes coaxially toward the front in the axial direction of the hexagonal shaft 3, and the hexagonal shaft 3 and driver bit 4 are structured to be integrated in terms of metal structure.

[0024] The processing steps for obtaining the wrench structure 1 described above are comprised of a cutting step in which a cone-shaped body 4a, such as a truncated cone, is cut out from the tip surface of the hexagonal shaft 3, as shown in FIG. 5(a), and a groove cutting step in which four grooves 5, the length of which runs along the axial direction of the hexagonal shaft 3, are machined on the outer surface extending from the cone-shaped body 4a to the hexagonal shaft 3, between the apex 4b of the cone-shaped body 4a and a position axially rearward and midway behind the tip surface of the hexagonal shaft 3, as shown in FIG. 5(b). First, in the cutting step, the excess length secured at the tip side of the hexagonal shaft 3 is cut out with a cutting tool B, so that the apex 4b at the tip side becomes flat or flat cone-shaped and is arranged coaxially with the hexagonal shaft 3, and a cone-shaped body 4a is cut out with a protruding height corresponding to the depth of the cross-shaped groove provided in the head of the wood screw.

[0025] Next, in the groove cutting process, four grooves 5 meeting the above-mentioned conditions are machined on the outer surface extending from the conical body 4a to the hexagonal shaft body 3, and these grooves 5 form the conical body 4a into a driver bit 4 having a cross-shaped tip.

[0026] The hexagonal shaft 3 has a hexagonal cross-sectional shape that fits the hexagonal hole in a bolt of a specified size and a length that ensures sufficient fit into the hexagonal hole, in order to tighten or loosen a bolt with a hexagonal hole in the head. In the case of Figure 1, the shaft 2 is a straight circular shaft with a slightly smaller diameter than the hexagonal shaft 3, and an example for use in an automatic machine is shown in which an attachment engagement portion 6 for a rotating tool is machined on the rear end. However, for example, a wrench for manual operation may be formed by using a single hexagonal shaft material and bending the tip side of the straight portion that serves as the gripping portion of a specified length at a right angle, and providing a driver bit 4 on the tip surface of this wrench.

[0027] In order to make the above-mentioned conical body 4a into a cross-shaped driver bit 4, a groove 5 is provided on the outer surface extending from the conical body 4a to the hexagonal shaft body 3, and is cut with a milling cutter F on a milling machine as shown in Figures 4 and 5(b) so that the cross-sectional shape is V-shaped and the maximum opening width a is set narrower than the length b of one side of the hexagon at the tip face of the hexagonal shaft body 3, and by using the milling cutter F, the longitudinal direction of this groove 5 at the bottom forms a single circular arc.

[0028] Furthermore, the four grooves 5, which are equally spaced around the periphery of the hexagonal shaft body 3, are set so that, as shown in Figure 4, the center line c of each groove 5 in the width direction coincides with one of the corners of the hexagon on the end face of the hexagonal shaft body 3, and the depth direction is arranged along the radial center line connecting the one corner and the axis of the hexagonal shaft body 3. By cutting such four grooves 5, the conical body 4a is cut at four positions, and the driver bit 4 has a cross shape when viewed from the front, with engagement protrusions 4c extending in all four directions from the center.

[0029] At this time, the radial center line connecting the axis of the hexagonal shaft body 3 and one corner of the hexagon coincides with the widthwise center line c of the groove 5, and the engaging protrusion 4c located adjacent to the groove 5 of the driver bit has its widthwise center line d at an angle of 45° to the center line c.

[0030] As shown in Figure 4, in the arrangement of the hexagon on the tip face of the hexagonal shaft 3 as described above and the four equally spaced grooves 5, if the center line c of any one of the grooves 5 in the width direction coincides with one corner of the hexagon on the end face of the hexagonal shaft 3, the groove 5 located on the opposite radial side will also coincide with a corner located on the opposite radial side of the hexagon, and the remaining two grooves 5 will be arranged to open at the longitudinal middle part of the straight sides of the hexagon.

[0031] Due to the arrangement of the four grooves 5 relative to the hexagonal shaft 3, four corners of the hexagon can be left at the tip of the hexagonal shaft 3 as points of force when tightening or loosening the bolt. Furthermore, the base of each of the cross-shaped engaging ridges 4c of the driver bit 4 extends between adjacent grooves 5 toward the remaining four corners of the hexagon, reaching the tip surface of the hexagonal shaft 3. This ensures a sufficient amount of connection between the tip surface of the hexagonal shaft 3 and the base of the driver bit 4, thereby ensuring sufficient strength of the hexagonal shaft 3 as a hex wrench and the strength of the driver bit 4.

[0032] The wrench structure of this invention is configured as described above, with the hexagonal shaft 3 of a predetermined length being made from a single piece of material and coaxially attached to the tip of the shaft 2, which serves as a rod-shaped material. First, lathe processing is used for the cutting process, and a cutting tool B is used to cut off a predetermined length from the tip side of the hexagonal shaft 3, to form a conical body 4a with a flat apex 4b on the new tip surface of the hexagonal shaft 3, which protrudes forward in the axial direction from the tip surface of the hexagonal shaft 3.

[0033] Next, a milling machine is used for the groove cutting process, and a milling cutter F is used to cut a groove 5 in the hexagonal shaft 3 on which the pyramidal body 4a is formed, the groove 5 having its length aligned with the axial direction of the hexagonal shaft 3, between the apex of the pyramidal body 4a and a midway position axially rearward of the tip surface of the hexagonal shaft 3.

[0034] By cutting four such grooves 5 at equal intervals in the circumferential direction of the hexagonal shaft body 3, the cone-shaped body 4a is formed into a driver bit 4 having a cross-shaped tip.

[0035] During the above-mentioned groove cutting process, the opening width of the groove 5 is made shorter than one side of the hexagonal shape of the end face of the hexagonal shaft body 3, and the positioning of this groove 5 relative to the hexagonal shaft body 3 is such that the center line in the width direction of one groove 5 coincides with one corner of the hexagon at the end face of the hexagonal shaft body 3, thereby ensuring that the four corners at the tip of the hexagonal shaft body 3 can be used as points of action for the hexagonal socket bolt and maintaining the strength of the hexagonal wrench.

[0036] With this type of wrench structure, when tightening or loosening a hexagonal socket bolt, the hexagonal shaft 3 acts as a wrench, with its tip fitting into the hexagonal socket to perform the work, and when tightening or loosening a cross-shaped grooved wood screw, a driver bit 4 is used.When fixing or removing a single component to a desired part using a hexagonal socket bolt and a cross-shaped grooved wood screw, the work can be performed continuously with one tool, and there is no need to change tools, making work efficient.

[0037] In addition, the driver bit 4 protruding from the tip of the hexagonal shaft body 3 has a short protrusion amount corresponding to the depth of the groove of the cross-shaped grooved wood screw, so when the hexagonal shaft body 3 is inserted into the hexagonal hole of the hexagonal socket bolt, the driver bit 4 does not get in the way, and the axial fit between the hexagonal hole and the hexagonal shaft body 3 and the resulting rotational transmission strength can be sufficiently secured. [Explanation of symbols]

[0038] 1 Wrench structure 2-axis body 3 Hexagonal shaft 4 Driver Bits 4a pyramid 4b Top 4c Engagement protrusion 5 Groove B Cutting tool F Milling cutter

Claims

1. A wrench structure in which a driver bit is integrally formed from the same material at the end of a hexagonal shaft that serves as a wrench, a conical body with a flat top is protruded from the tip surface of the hexagonal shaft in a coaxial arrangement, and a groove is provided on the outer surface extending from this conical body to the hexagonal shaft, between the top of the conical body and a position axially rearward and midway behind the tip surface of the hexagonal shaft, with the length direction of the groove running along the axial direction of the hexagonal shaft, and four of these grooves are provided at equal intervals around the circumferential direction of the hexagonal shaft, thereby forming the conical body into a driver bit with a cross shape when viewed from the tip.

2. The wrench structure according to claim 1, characterized in that the groove has a V-shaped cross section, the maximum width of which is set narrower than the length of one side of the hexagon at the end face of the hexagonal shaft body, and the entire length of the groove in the longitudinal direction at the bottom thereof forms a single circular arc.

3. The wrench structure according to claim 1 or 2, characterized in that the arrangement of the grooves in the circumferential direction of the hexagonal shaft body is such that the center line in the width direction of any one of the grooves coincides with one of the corners of the hexagon on the end face of the hexagonal shaft body, and the depth direction is arranged along the radial center line connecting the one corner and the axis of the hexagonal shaft body, and one length direction of the cross-shaped engagement protrusion of the driver bit adjacent to the groove is at a positional relationship of 45° to the radial center line connecting the one corner and the axis of the hexagonal shaft body.

4. A manufacturing method for a wrench structure comprising a cutting step of cutting out a cone-shaped body with a flat top from the tip surface of a hexagonal shaft that serves as a wrench so that it protrudes coaxially with the hexagonal shaft, and a groove cutting step of cutting four equally spaced grooves around the periphery of the hexagonal shaft on the outer surface extending from the cone-shaped body to the hexagonal shaft, between the top of the cone-shaped body and a position axially inward relative to the end face of the hexagonal shaft.

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