A drill bit extrusion molding die

Abstract

This utility model provides a drill bit extrusion molding die, belonging to the field of mechanical technology. It solves the problem of high manufacturing cost of drill bits caused by existing molds. This drill bit extrusion molding die includes an upper die, a lower die, and a liftable extrusion rod. The bottom wall of the upper die has an upper cavity, and the lower die has a corresponding through-hole. The upper end of the extrusion rod extends into the through-hole, and a punch is vertically formed on the top wall of the extrusion rod. The upper cavity, the punch, the top surface of the extrusion rod, and the upper section of the through-hole form a molding cavity. At least one protrusion is horizontally formed on the bottom wall of the lower die, with its inner end extending into the upper cavity. The inner end face of the protrusion is an arc-shaped convex surface, and the upper side of the arc-shaped convex surface extends to the inner wall of the upper cavity. A clearance groove is horizontally formed on the top wall of the lower die. The number of protrusions and clearance grooves are the same, and their positions correspond one-to-one. The protrusions are inserted into the corresponding clearance grooves so that the arc-shaped convex surface forms a protrusion on the inner wall of the molding cavity for forming a chip removal groove for the drill bit. This drill bit extrusion molding die results in low manufacturing cost for drill bits.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to an extrusion molding die, particularly a drill bit extrusion molding die. Background Technology

[0002] A rock drill is a tool used to directly extract stone. It drills holes in the rock strata to insert explosives to blast open the rock, thereby completing the extraction of stone or other stone excavation projects.

[0003] The drill bit is the working cutting tool of a rock drill, and its structure is as follows: Figure 1 As shown, the drill bit body 7 includes a drill bit body 7 with a central hole. The central hole is a blind hole, and the upper end of the central hole is closed and the lower end is open. At least one chip removal groove 7a is distributed circumferentially on the upper outer wall of the drill bit body 7.

[0004] In actual machining, the drill bit body is generally machined first, and then the chip removal groove is formed by machining. The forming method of the drill bit body is as described in the rock drilling drill bit shell warm extrusion forming die (application number: 201420576611.6) disclosed in the Chinese Patent Database. It includes a top tie rod, a lower die base, and a vertically downward-facing punch. An upper die base is provided above the lower die base. A lower die cavity is set on the lower die base by fitting with a groove on the lower die base. The upper die cavity is assembled in the upper die cavity assembly hole of the upper die base, with the lower end of the upper die cavity fitting with the upper end of the lower die cavity. The punch fits with the upper die cavity. A pad is provided above the upper die cavity, and a top plate is provided below the lower die base. The pad, upper die base, lower die base, and top plate are connected by vertically arranged connecting rods evenly distributed along the circumference. The top plate is connected to the top tie rod.

[0005] The aforementioned mold can only form the main body of the drill bit; the chip removal groove still needs to be formed by machining. Due to the requirements of the drill bit's working conditions, it needs good wear resistance and hardness, and is generally made of 30CrNiMoV alloy steel. This material is expensive in the market, and machining will cause a lot of material waste, resulting in high drill bit processing costs. Utility Model Content

[0006] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a drill bit extrusion molding die that can reduce the cost of drill bit processing.

[0007] The objective of this utility model can be achieved through the following technical solution: A drill bit extrusion molding die includes an upper die, a lower die, and a liftable extrusion rod. The upper die has an upper cavity on its bottom wall, and the lower die has a corresponding through-hole. The upper end of the extrusion rod extends into and blocks the lower section of the through-hole. A punch is vertically formed on the top wall of the extrusion rod. The upper cavity, punch, top surface of the extrusion rod, and upper section of the through-hole form a molding cavity for forming the drill bit body. The lower die bottom wall has at least one horizontally formed protrusion, and the protrusion… The inner end extends to the upper cavity, and the inner end face of the protrusion is an arc-shaped convex surface, with the upper side of the arc-shaped convex surface extending to the inner wall of the upper cavity. The arc-shaped convex surface is inclined so that the upper side of the arc-shaped convex surface is closer to the central axis of the upper cavity than the lower side of the arc-shaped convex surface. A relief groove matching the protrusion is horizontally opened on the top wall of the lower mold, and the inner end of the relief groove extends to the inner wall of the forming hole. The number of protrusions and relief grooves are the same and their positions correspond one-to-one. The protrusion is inserted into the corresponding relief groove so that the arc-shaped convex surface forms a protrusion on the inner wall of the forming cavity for forming the chip removal groove of the drill bit.

[0008] In actual assembly, this extrusion molding die is mounted on a hydraulic press, which includes an upper plate, a middle plate, a lower plate, an upper hydraulic cylinder, and a lower hydraulic cylinder. The upper and lower plates are driven to rise and fall by the upper and lower hydraulic cylinders, respectively, while the middle plate is fixed. Specifically, the upper die is fixed to the bottom of the upper plate, the lower die is fixed to the top of the middle plate, and the extrusion rod is fixed to the top of the lower plate.

[0009] In use, the heated solid cylindrical blank is placed into the forming hole and supported by the punch. Then the upper die moves down and presses against the lower die to close the mold. Then the extrusion rod moves up to press the blank into the forming cavity and shape it according to the shape of the forming cavity. After the forming is completed, the upper die moves up to open the mold and the formed drill bit is taken out.

[0010] This molding die forms both the drill bit body and the chip removal groove in a single extrusion, thus avoiding the cutting and forming operation of the chip removal groove in existing technologies, thereby effectively reducing material waste and lowering processing costs.

[0011] In the aforementioned extrusion die, the protrusion is elongated and its length extends radially along the upper cavity to increase the connection area between the protrusion and the upper die, enhance the protrusion's compressive strength, and ensure a stable extrusion process.

[0012] In the aforementioned drill bit extrusion molding die, the clearance groove is provided through to facilitate the processing and forming of the clearance groove.

[0013] In the aforementioned drill bit extrusion molding die, the lower end of the protrusion is a guide section with an approximate V-shaped cross-section, and the lower end of the clearance groove has a V-shaped cross-section that matches the guide section. The V-shaped fit between the guide section and the lower end of the clearance groove effectively enhances the positional accuracy of the arc-shaped convex surface and improves the forming quality and accuracy of the chip removal groove.

[0014] In the aforementioned drill bit extrusion molding die, the extrusion rod has an axially penetrating material hole, with the upper end of the material hole located on the top wall of the punch; an ejector rod is slidably installed inside the material hole. During installation, the aforementioned hydraulic press also includes an ejector hydraulic cylinder, which moves synchronously with the lower plate. The lower end of the ejector rod is connected to the ejector hydraulic cylinder to achieve lifting and lowering, used to eject the formed drill bit from the lower die for easy material removal.

[0015] Compared with existing technologies, this drill bit extrusion molding die has the following advantages:

[0016] 1. This forming die can form both the drill bit body and the chip removal groove in one extrusion, thus avoiding the chip removal groove cutting and forming operation in the prior art, thereby effectively reducing material loss and reducing processing costs.

[0017] 2. The guide section and the lower end of the clearance groove are connected by a V-shape, which can effectively enhance the positional accuracy of the arc-shaped convex surface and improve the forming quality and accuracy of the chip removal groove. Attached Figure Description

[0018] Figure 1 This is a 3D schematic diagram of the drill bit.

[0019] Figure 2 This is a three-dimensional schematic diagram of the extrusion molding die for the drill bit.

[0020] Figure 3 This is a cross-sectional schematic diagram of the extrusion molding die for the drill bit.

[0021] Figure 4 This is a 3D schematic diagram of the upper mold.

[0022] Figure 5 This is a three-dimensional schematic diagram of the lower mold.

[0023] Figure 6 This is a schematic diagram of the drill bit extrusion molding die after it has been installed in a hydraulic press.

[0024] In the diagram, 1 is the upper die; 1a is the upper cavity; 1b is the protrusion; 1b1 is the arc-shaped convex surface; 1b2 is the guide; 2 is the lower die; 2a is the forming hole; 2b is the clearance groove; 3 is the extrusion rod; 3a is the punch; 4 is the forming cavity; 5 is the hydraulic press; 5a is the upper plate; 5b is the middle plate; 5c is the lower plate; 5d is the upper hydraulic cylinder; 5e is the lower hydraulic cylinder; 6 is the ejector rod; 7 is the drill bit body; 7a is the chip removal groove. Detailed Implementation

[0025] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0026] like Figure 2 and Figure 3As shown, this extrusion die for the drill bit includes an upper die 1, a lower die 2, and a liftable extrusion rod 3.

[0027] in,

[0028] The upper mold 1 has an upper cavity 1a on its bottom wall, and preferably the upper cavity 1a and the upper mold 1 are coaxially arranged to facilitate design and layout.

[0029] A forming hole 2a is vertically penetrating the lower mold 2, and the central axes of the forming hole 2a and the upper cavity 1a are collinear. The forming hole 2a is divided into an upper section and a lower section distributed along the axial direction of the forming hole 2a. The shape and size of the upper end of the extrusion rod 3 are matched with the lower section of the forming hole 2a, and the upper end of the extrusion rod 3 can extend into and block the lower section of the forming hole 2a. At this time, the side wall of the upper end of the extrusion rod 3 contacts the inner wall of the lower section of the forming hole 2a, and preferably the two are in contact through a circumferential surface fit.

[0030] like Figures 2 to 5 As shown, a punch 3a is vertically formed on the top wall of the extrusion rod 3, and the punch 3a and the extrusion rod 3 are coaxially arranged. At this time, a forming cavity 4 for forming the drill bit body 7 is formed between the inner wall of the upper cavity 1a, the punch 3a, the top surface of the extrusion rod 3, and the upper section of the inner wall of the forming hole 2a. At least one protrusion 1b is horizontally formed on the bottom wall of the lower die 2, and when the number of protrusions 1b is ≥2, multiple protrusions 1b are distributed circumferentially along the upper die 1. The number and position of the protrusions 1b are specifically determined according to the chip removal groove 7a on the actual drill bit.

[0031] like Figure 3 and Figure 4 As shown, the two ends of the protrusion 1b are an inner end and an outer end, respectively, with the outer end of the protrusion 1b positioned close to the outer surface of the upper mold 1. The inner end of the protrusion 1b extends into the upper cavity 1a, and the inner end face of the protrusion 1b is an arc-shaped convex surface 1b1, with the upper side of the arc-shaped convex surface 1b1 extending to the inner wall of the upper cavity 1a. The arc-shaped convex surface 1b1 is inclined so that the upper side of the arc-shaped convex surface 1b1 is closer to the central axis of the upper cavity 1a than the lower side of the arc-shaped convex surface 1b1. A clearance groove 2b with a shape and size matching the protrusion 1b is horizontally opened on the top wall of the lower mold 2, and the inner end of the clearance groove 2b extends into the inner wall of the forming hole 2a, i.e., the inner end of the clearance groove 2b is open at this time. The number of protrusions 1b and clearance grooves 2b are the same, and their positions correspond one-to-one. The protrusion 1b is inserted into the corresponding clearance groove 2b so that the arc-shaped convex surface 1b1 forms a protrusion on the inner wall of the forming cavity 4 for forming the chip removal groove 7a of the drill bit.

[0032] In actual assembly, such as Figure 6As shown, the extrusion molding die is mounted on a hydraulic press 5, which is an existing product purchased directly from an external supplier. The hydraulic press 5 includes an upper plate 5a, a middle plate 5b, a lower plate 5c, an upper hydraulic cylinder 5d, and a lower hydraulic cylinder 5e. The upper plate 5a and lower plate 5c are driven to rise and fall by the upper hydraulic cylinder 5d and the lower hydraulic cylinder 5e, respectively. The middle plate 5b is fixed in place. The upper die 1 is fixed to the bottom of the upper plate 5a, the lower die 2 is fixed to the top of the middle plate 5b, and the extrusion rod 3 is fixed to the top of the lower plate 5c.

[0033] In use, the heated solid cylindrical blank is placed into the forming hole 2a and supported by the punch 3a. Then, the upper die 1 moves down and presses against the lower die 2 to close the mold. Next, the extrusion rod 3 moves up to press the blank into the forming cavity 4 and shape it according to the shape of the forming cavity 4. After forming is completed, the upper die 1 moves up to open the mold and remove the formed drill bit. The arc-shaped convex surface 1b1 is set obliquely upward relative to the upper die 1, which facilitates the forming of the chip removal groove 7a and the separation of the upper die 1 from the formed drill bit.

[0034] This molding die forms both the drill bit body 7 and the chip removal groove 7a in a single extrusion, thus avoiding the cutting and forming operation of the chip removal groove 7a in the prior art, thereby effectively reducing material loss and lowering processing costs.

[0035] To further explain, the protrusion 1b is elongated, and its length extends radially along the upper cavity 1a to increase the connection area between the protrusion 1b and the upper die 1, thereby enhancing the compressive strength of the protrusion 1b and ensuring stable extrusion. Preferably, the outer end face of the protrusion 1b is flush with the outer surface of the upper die 1 to maximize the length of the protrusion 1b. The clearance groove 2b is through-hole shaped to facilitate its machining.

[0036] Furthermore, the lower end of the protrusion 1b is a guide portion 1b2 with a cross-section approximately V-shaped, and the lower end of the clearance groove 2b has a cross-section that matches the guide portion 1b2. The V-shaped fit between the guide portion 1b2 and the lower end of the clearance groove 2b effectively enhances the positional accuracy of the arc-shaped convex surface 1b1 and improves the forming quality and accuracy of the chip removal groove 7a.

[0037] In the actual product, the extrusion rod 3 has an axially penetrating material hole, and the upper end of the material hole is located on the top wall of the punch 3a. Preferably, the material hole and the extrusion rod 3 are coaxially arranged. An ejector rod 6 is slidably arranged up and down inside the material hole. During installation, the hydraulic press 5 also includes an ejector hydraulic cylinder, which moves synchronously with the lower plate 5c. The lower end of the ejector rod 6 is connected to the ejector hydraulic cylinder to achieve lifting and lowering, which is used to eject the formed drill bit from the lower die 2 for easy material removal.

[0038] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A drill bit extrusion molding die, comprising an upper die (1), a lower die (2), and a liftable extrusion rod (3), wherein the lower die (2) has a corresponding through-hole (2a) on its bottom wall, the upper end of the extrusion rod (3) extends into and blocks the lower section of the forming hole (2a), and a punch (3a) is vertically formed on the top wall of the extrusion rod (3), wherein the upper cavity (1a), the punch (3a), the top surface of the extrusion rod (3), and the upper section of the forming hole (2a) form a molding cavity (4) for forming a drill bit body (7), characterized in that, At least one protrusion (1b) is horizontally formed on the bottom wall of the lower mold (2), and the inner end of the protrusion (1b) extends to the upper cavity (1a). The inner end face of the protrusion (1b) is an arc-shaped convex surface (1b1), and the upper side of the arc-shaped convex surface (1b1) extends to the inner wall of the upper cavity (1a). The arc-shaped convex surface (1b1) is inclined so that the upper side of the arc-shaped convex surface (1b1) is closer to the central axis of the upper cavity (1a) than the lower side of the arc-shaped convex surface (1b1). Line; The top wall of the lower mold (2) is horizontally provided with a relief groove (2b) that matches the protrusion (1b), and the inner end of the relief groove (2b) extends to the inner wall of the forming hole (2a). The number of protrusions (1b) and relief grooves (2b) are the same and their positions correspond one to one. The protrusions (1b) are inserted into the corresponding relief grooves (2b) so that the above-mentioned arc-shaped convex surface (1b1) forms a protrusion on the inner wall of the forming cavity (4) for forming the chip removal groove (7a) of the drill bit.

2. The drill bit extrusion molding die according to claim 1, characterized in that, The aforementioned protrusion (1b) is elongated, and the length of the protrusion (1b) extends radially along the upper cavity (1a).

3. The drill bit extrusion molding die according to claim 1 or 2, characterized in that, The aforementioned clearance groove (2b) is provided through.

4. The drill bit extrusion molding die according to claim 3, characterized in that, The lower end of the protrusion (1b) is a guide (1b2) with a cross-section that is approximately V-shaped, and the lower end of the clearance groove (2b) has a cross-section that matches the guide (1b2).

5. The drill bit extrusion molding die according to claim 1, characterized in that, The extrusion rod (3) has an axially penetrating material hole, and the upper end of the material hole is located on the top wall of the punch (3a); an ejector rod (6) is slidably installed inside the material hole.

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