Cutter bar for machining internal threaded hole and internal threaded hole machining method

Abstract

The invention discloses a cutter bar for machining an internal threaded hole. The cutter bar comprises a cutter bar body, a dovetail is arranged at the front end of the cutter bar body, a cutter hole is formed in the cutter bar body, a sliding block is installed at the dovetail, and a threaded cutter is fixed at the cutter hole through a clamping screw. The invention further discloses an internal threaded hole machining method which is specifically implemented according to the following steps that the two side edges of the threaded cutter are ground to be symmetrical; when the threaded cutter is clamped, the front cutter face of the cutter is perpendicular to the rotating direction of the thread; during thread machining, the sliding block can just slide in the thread bottom hole; a tool nose falls on the center line of the part; and the sliding block does not need to be separated from the threaded bottom hole during retracting each time. The internal thread machining tool bar is simple in structure and low in manufacturing cost, the rigidity of the tool bar during internal thread machining is enhanced, the problems of low machining precision and low production efficiency during internal thread machining in a traditional method are solved, and the internal thread machining tool bar has high practicability.

Description

Technical Field

[0001] The invention belongs to the field of mechanical equipment manufacturing and relates to a tool rod for machining an internal threaded hole. In addition, the invention also relates to a method for machining an internal threaded hole. Background Art

[0002] In the process of machining internal threaded holes on a lathe, the conventional method is generally to perform rough turning first to remove most of the machining allowance. During the rough turning process, a larger back cutting amount and number of passes can be used to quickly form the thread groove. After rough turning, a certain amount of allowance will be left on the thread tooth side and bottom surface, which is convenient for subsequent fine turning. After the rough turning process is completed, fine turning is performed. The main purpose of fine turning is to ensure the thread size accuracy and surface roughness. During the fine turning process, a smaller back cutting amount and number of passes need to be used, and the cutting amount and cutting speed need to be strictly controlled. At the same time, attention should be paid to the clamping and tool setting accuracy of the tool to ensure the accuracy of the thread tooth angle. Workpieces processed using conventional methods often have problems such as ripples on both sides of the thread after processing, large roughness, taper (flare) on the workpiece, different tightness when checking from both ends with a plug gauge, and low production efficiency. Conventional processing methods, due to the limitation of workpiece size, often use thin and long tool bars with poor rigidity. When cutting, the tool head works on two or three sides, and the cutting force is large, which can easily cause vibration, resulting in ripples on the thread surface. After the ripples are formed, it is difficult to eliminate them. In addition, conventional processing methods also have poor tool bar rigidity, and there is a "cutting-off" phenomenon during processing, resulting in taper of the thread. In order to eliminate the ripples and taper, the cutting amount has to be reduced and the number of passes has to be increased, especially in the process of mass production, the production efficiency is very low. In summary, the conventional processing methods have the problems of low workpiece processing accuracy and low production efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a tool bar for machining internal threaded holes, which solves the problems of low workpiece machining accuracy and low production efficiency in the prior art.

[0004] Another object of the present invention is to provide the above-mentioned internal thread hole processing method.

[0005] The technical solution adopted by the present invention is that a tool rod for processing internal threaded holes includes a tool rod body, the tool rod body is divided into a working section and an installation section, a dovetail is opened on the top wall at the end of the working section, a sliding block is slidably connected above the dovetail, a pair of top screw holes are opened on the side wall of the working section away from the installation section, a tool hole is opened on the side wall adjacent to the top screw hole, a threaded tool is installed in the tool hole, the top screw hole is communicated with the tool hole, a clamping screw is installed in the top screw hole, and the clamping screw is inserted into the tool hole through the top screw hole.

[0006] The present invention is also characterized in that: A dovetail groove is provided at the bottom of the sliding block, the dovetail is engaged with the dovetail groove, an outer arc is provided at the top of the sliding block, an end face chamfer is provided on the side wall of the sliding block, an adjustment gasket set is clamped between the top inner wall of the tool hole and the thread cutter, a bottom screw hole is provided at the bottom of the tool hole, and an adjustment screw is installed in the bottom screw hole.

[0007] Another technical solution adopted by the present invention is to provide the above-mentioned internal thread hole processing method, which is specifically carried out according to the following steps: Step 1: Fix the tool bar body on the tool holder, and install the cutting edge of the thread tool downward into the tool hole of the tool bar body; Step 2: Move the tool holder so that the end chamfer enters the thread bottom hole, and insert the adjustment shim set so that the tool tip falls on the center line of the part; Step 3: Move the tool holder to disengage the sliding block from the thread bottom hole, and tighten the thread cutter with the clamping screw; Step 4: Move the tool holder so that the end face chamfer enters the thread bottom hole; Step 5: Adjust the position of the tool tip according to the first cutting amount; Step 6: Start the first thread cutting; Step 7: After cutting is completed, the tool is withdrawn; Step 8: Adjust the position of the tool tip according to the second cutting amount; Step 9: Start the second thread cutting; The subsequent steps are the same as steps 7 to 9, and the cutting amount is gradually reduced.

[0008] The present invention is also characterized in that: Before installing the thread cutter into the tool bar body, adjust the two side cutting edges symmetrically. During the tool adjustment process, ensure that the gap between the highest point of the outer arc and the bottom hole of the thread is 0.05-0.1mm. When cutting threads, wait for the processed parts to rotate forward, and after the workpiece is processed, make 1-2 empty passes.

[0009] The beneficial effects of the present invention are as follows: the present invention has a simple structure and low manufacturing cost. By assembling a sliding block at the top of the end of the working section of the tool bar body, since the diameter of the outer arc surface of the sliding block is smaller than the diameter of the thread bottom hole of the workpiece, the sliding block can slide in the dovetail of the tool bar body through the dovetail groove, and the sliding process does not affect the radial feed of the tool. During processing, the workpiece rotates forward, and the cutting force is pressed downward. Due to the reverse clamping of the cutter head, the cutting resistance is upward, so that the highest point of the outer arc of the sliding block contacts the thread bottom hole of the workpiece, eliminating the vibration of the tool bar. This floating support strengthens the rigidity of the tool bar and reduces the phenomenon of tool yielding during the thread cutting process, thereby improving the surface quality of the workpiece and avoiding taper. Due to the enhanced rigidity of the tool bar, the feed amount can be increased each time, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1It is a structural schematic diagram of a tool bar device for machining an internal threaded hole according to the present invention; Figure 2 It is an AA view of the tool bar device for machining an internal threaded hole of the present invention; Figure 3 A schematic diagram of a thread tool of a tool bar device for machining an internal threaded hole of the present invention; Figure 4 It is a structural schematic diagram of a tool bar body for machining an internal threaded hole according to the present invention; In the figure, 1. tool bar body, 2. sliding block, 3. threaded tool, 4. clamping screw, 5. adjusting screw, 6. adjusting shim set, 101. dovetail, 102. tool hole, 103. top screw hole, 104. bottom screw hole, 201. dovetail groove, 202. outer arc surface, 203. end face chamfer. DETAILED DESCRIPTION

[0011] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] Tool bar for machining internal threaded holes, such as Figure 1 As shown, it includes a tool bar body 1, which is divided into a working section 7 and a mounting section 8. The top of the end of the working section 7 is slidably connected with a sliding block 2. A pair of top screw holes 103 are opened on the end face of the working section 7. A through tool hole 102 is opened on the side of the working section 7. A threaded tool 3 is installed in the tool hole 102. The top screw hole 103 is connected to the tool hole 102, and a clamping screw 4 is installed in the top screw hole 103. A dovetail groove 201 is opened at the bottom of the sliding block 2, and a dovetail 101 matching the dovetail groove 201 is provided on the top surface of the working section 7. The surface of the sliding block 2 opposite to the dovetail groove 201 is an outer arc surface 202 axially parallel to the tool bar body 1, and an end face chamfer 203 is opened at the top corner of the sliding block 2.

[0013] like Figure 2 As shown, an adjusting shim set 6 is sandwiched between the inner wall of the top of the tool hole 102 and the threaded tool 3. A bottom screw hole 104 is formed at the bottom of the tool hole 102, and an adjusting screw 5 is installed in the bottom screw hole 104.

[0014] The internal thread hole processing method specifically comprises the following steps: Step 1: Fix the tool bar body 1 on the tool holder, and install the cutting edge of the thread tool 3 downward into the tool hole 102 of the tool bar body 1; Step 2: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole, and insert the adjusting shim set 6 so that the tool tip falls on the center line of the part; Step 3: Move the tool holder to disengage the sliding block 2 from the thread bottom hole, and tighten the thread cutter 3 with the clamping screw 4; Step 4: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole; Step 5: Adjust the position of the tool tip according to the first cutting amount; Step 6: Start the first thread cutting; Step 7: After cutting is completed, the tool is withdrawn; Step 8: Adjust the position of the tool tip according to the second cutting amount; Step 9: Start the second thread cutting; The subsequent steps are synchronized from step seven to step nine, and the cutting amount is gradually reduced.

[0015] Embodiment 1: A tool bar for processing an internal threaded hole comprises a tool bar body 1, which is divided into a working section 7 and a mounting section 8. A dovetail 101 is provided on the top wall at the end of the working section 7, and a sliding block 2 is slidably connected above the dovetail 101. A pair of top screw holes 103 are provided on the side wall of the working section 7 away from the mounting section 8, and a tool hole 102 is provided on the side wall adjacent to the top screw hole 103. A threaded tool 3 is installed in the tool hole 102, and the top screw hole 103 communicates with the tool hole 102. A clamping screw 4 is installed in the top screw hole 103, and the clamping screw 4 is inserted into the tool hole 102 through the top screw hole 103. Fastening the threaded tool with a clamping screw can make the disassembly and replacement of the threaded tool relatively simple, which helps to reduce production costs and downtime during maintenance.

[0016] Embodiment 2: A tool bar for processing an internal threaded hole comprises a tool bar body 1, which is divided into a working section 7 and an installation section 8. A dovetail 101 is provided on the top wall at the end of the working section 7, and a sliding block 2 is slidably connected above the dovetail 101. A pair of top screw holes 103 are provided on the side wall of the working section 7 away from the installation section 8, and a tool hole 102 is provided on the side wall adjacent to the top screw hole 103. A threaded tool 3 is installed in the tool hole 102, and the top screw hole 103 is communicated with the tool hole 102. A clamping screw 4 is installed in the top screw hole 103, and the clamping screw 4 is inserted into the tool hole 102 through the top screw hole 103. A dovetail groove 201 is provided at the bottom of the sliding block 2, and the dovetail 101 is engaged with the dovetail groove 201. An outer arc 202 is provided on the top of the sliding block 2. The side wall of the sliding block 2 is provided with an end chamfer 203, and the sliding block 2 can slide in the dovetail of the tool rod body 1 through the dovetail groove 201. The sliding process does not affect the radial feed of the tool. The locking design of the dovetail groove 201 and the dovetail 101 ensures the close connection and precise positioning between the sliding block and the tool rod, which helps to reduce vibration and deviation during the processing, thereby improving the accuracy of thread processing. The outer arc can enhance the carrying capacity of the sliding block, so that it can carry loads from all directions, thereby improving the stability and reliability of the entire device. The side wall of the sliding block 2 is connected with the outer arc 202 with an end chamfer 203. The end chamfer can reduce the sharpness of the edge of the sliding block and reduce the risk of scratching other parts or operators during assembly and use.

[0017] Embodiment 3: A tool bar for processing internal threaded holes includes a tool bar body 1, which is divided into a working section 7 and an installation section 8. A dovetail 101 is opened on the top wall at the end of the working section 7, and a sliding block 2 is slidably connected above the dovetail 101. A pair of top screw holes 103 are opened on the side wall of the working section 7 away from the installation section 8, and a tool hole 102 is opened on the side wall adjacent to the top screw hole 103. A threaded tool 3 is installed in the tool hole 102, and the top screw hole 103 is communicated with the tool hole 102. A clamping screw 4 is installed in the top screw hole 103, and the clamping screw 4 is inserted into the tool hole 102 through the top screw hole 103. An adjustment gasket group 6 is clamped between the top inner wall of the tool hole 102 and the threaded tool 3. The addition of the adjustment gasket group 6 further increases the flexibility and adaptability of the adjustment. By replacing adjustment gaskets of different thicknesses, the height and position of the tool can be fine-tuned to meet the needs of different workpieces and cutting conditions.

[0018] Embodiment 4: A tool bar for processing an internal threaded hole comprises a tool bar body 1, which is divided into a working section 7 and an installation section 8. A dovetail 101 is provided on the top wall at the end of the working section 7, and a sliding block 2 is slidably connected above the dovetail 101. A pair of top screw holes 103 are provided on the side wall of the working section 7 away from the installation section 8, and a tool hole 102 is provided on the side wall adjacent to the top screw hole 103. A threaded tool 3 is installed in the tool hole 102, and the top screw hole 103 is communicated with the tool hole 102. A clamping screw 4 is installed in the top screw hole 103, and the clamping screw 4 is inserted into the tool hole 102 through the top screw hole 103. A bottom screw hole 104 is provided at the bottom of the tool hole 102, and an adjustment screw 5 is installed in the bottom screw hole 104. The threaded tool and the adjustment gasket group are fastened together through the bottom screw hole by the adjustment screw, which can prevent the tool from loosening or falling off during the cutting process, thereby ensuring the stability and safety of the cutting process.

[0019] Embodiment 5: The method of using the tool bar device for processing internal threaded holes is implemented according to the following steps: Step 1: Fix the tool bar body 1 on the tool holder, and install the cutting edge of the thread tool 3 downward into the tool hole 102 of the tool bar body 1; Step 2: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole, and insert the adjusting shim set 6 so that the tool tip falls on the center line of the part; Step 3: Move the tool holder to disengage the sliding block 2 from the thread bottom hole, and tighten the thread cutter 3 with the clamping screw 4; Step 4: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole; Step 5: Adjust the position of the tool tip according to the first cutting amount; Step 6: Start the first thread cutting; Step 7: After cutting is completed, the tool is withdrawn; Step 8: Adjust the position of the tool tip according to the second cutting amount; Step 9: Start the second thread cutting; The subsequent steps are the same as steps 7 to 9, and the cutting amount is gradually reduced.

[0020] In addition, before the thread cutter 3 is installed into the tool rod 1, the two side edges are adjusted to be symmetrical. The symmetrical side edges can ensure that the amount of material removed on both sides of the tool is uniform during the cutting process, thereby avoiding uneven cutting force and causing thread shape distortion or dimensional deviation. At the same time, adjusting the two side edges to be symmetrical can reduce vibration and runout during the cutting process, making the tool more stable during the processing process, helping to reduce tool wear and improve processing efficiency and surface quality.

[0021] Embodiment 6: The method of using the tool bar device for processing internal threaded holes is implemented according to the following steps: Step 1: Fix the tool bar body 1 on the tool holder, and install the cutting edge of the thread tool 3 downward into the tool hole 102 of the tool bar body 1; Step 2: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole, and insert the adjusting shim set 6 so that the tool tip falls on the center line of the part; Step 3: Move the tool holder to disengage the sliding block 2 from the thread bottom hole, and tighten the thread cutter 3 with the clamping screw 4; Step 4: Move the tool holder so that the end face chamfer 203 enters the thread bottom hole; Step 5: Adjust the position of the tool tip according to the first cutting amount; Step 6: Start the first thread cutting; Step 7: After cutting is completed, the tool is withdrawn; Step 8: Adjust the position of the tool tip according to the second cutting amount; Step 9: Start the second thread cutting; The subsequent steps are the same as steps 7 to 9, and the cutting amount is gradually reduced.

[0022] During the tool adjustment process, the clearance between the highest point of the outer arc 202 and the bottom hole of the thread must be 0.05-0.1mm. When cutting threads, the workpiece rotates forward. The workpiece rotates forward, and the cutting force is pressed downward. Due to the reverse clamping of the cutter head, the cutting resistance is upward, so that the highest point of the outer arc of the sliding block in the tool bar device contacts the bottom hole of the workpiece thread, eliminating the vibration of the tool bar, strengthening the rigidity of the tool bar, reducing the vibration of the spindle, and being beneficial to improving the surface quality of the workpiece thread.

[0023] Embodiment 7: The method of using the tool bar device for processing internal threaded holes is implemented according to the following steps: Step 1: Fix the tool shank body 1 on the tool rest, and install the cutting edge of the threading tool 3 downward in the tool hole 102 of the tool shank body 1; Step 2: Move the tool rest to make the end chamfer 203 enter the bottom thread hole, insert the adjustment shim group 6, and make the tool tip fall on the part center line; Step 3: Move the tool rest to disengage the sliding block 2 from the bottom thread hole, and fasten the threading tool 3 with the clamping screw 4; Step 4: Move the tool rest to make the end chamfer 203 enter the bottom thread hole; Step 5: Adjust the position of the tool tip according to the first cutting parameters; Step 6: Start the first threading; Step 7: Retract the tool after cutting is completed; Step 8: Adjust the position of the tool tip according to the second cutting parameters; Step 9: Start the second threading; The subsequent steps are the same as Steps 7 to 9, and the cutting parameters are gradually reduced.

[0024] After the workpiece is machined to the required size, make the tool feed without cutting for 1 - 2 times. By making the tool feed without cutting, it is possible to further confirm whether the workpiece has achieved the required size and shape accuracy, which helps to ensure that each machining can achieve consistent quality and effect, thereby improving production efficiency and product quality. At the same time, by making the tool feed without cutting after the machining is completed, the direct contact time between the tool and the workpiece can be reduced, thereby extending the service life of the tool.

Claims

1. A tool bar for machining an internal threaded hole, comprising a tool bar body (1), characterized in that: The tool rod body (1) is divided into a working section (7) and a mounting section (8); the top of the end of the working section (7) is slidably connected to a sliding block (2); the end surface of the working section (7) is provided with a pair of top screw holes (103); the side surface of the working section (7) is provided with a through tool hole (102); a threaded tool (3) is installed in the tool hole (102); the top screw hole (103) is communicated with the tool hole (102); and a clamping screw (4) is installed in the top screw hole (103).

2. The tool bar for machining an internal threaded hole according to claim 1, characterized in that: The bottom of the sliding block (2) is provided with a dovetail groove (201), and the top surface of the working section (7) is provided with a dovetail (101) matching the dovetail groove (201).

3. The tool bar for machining an internal threaded hole according to claim 1, characterized in that: The surface of the sliding block (2) opposite to the dovetail groove (201) is an outer arc surface (202) axially parallel to the shank body (1), and an end face chamfer (203) is formed at the top corner of the sliding block (2).

4. The tool bar for machining an internal threaded hole according to claim 1, characterized in that: An adjusting gasket set (6) is sandwiched between the inner wall at the top of the tool hole (102) and the threaded tool (3).

5. The tool bar for machining an internal threaded hole according to claim 1, characterized in that: A bottom screw hole (104) is formed at the bottom of the tool hole (102), and an adjustment screw (5) is installed in the bottom screw hole (104).

6. A method for processing an internal threaded hole, characterized in that: The tool bar for machining an internal threaded hole according to any one of claims 1 to 5 is implemented in the following steps: Step 1: fix the tool bar body (1) on the tool holder, and install the cutting edge of the threading tool (3) downward into the tool hole (102) of the tool bar body (1); Step 2: Move the tool holder so that the end chamfer (203) enters the threaded bottom hole, and insert the adjusting shim set (6) so that the tool tip falls on the center line of the part; Step 3: Move the tool holder to disengage the sliding block (2) from the thread bottom hole, and tighten the thread cutter (3) with the clamping screw (4); Step 4: Move the tool holder so that the end face chamfer (203) enters the thread bottom hole; Step 5: Adjust the position of the tool tip according to the first cutting amount; Step 6: Start the first thread cutting; Step 7: After cutting is completed, the tool is withdrawn; Step 8: Adjust the position of the tool tip according to the second cutting amount; Step 9: Start the second thread cutting; The subsequent steps are synchronized from step seven to step nine, and the cutting amount is gradually reduced.

7. The internal thread hole machining method according to claim 6, characterized in that: Before the thread cutter (3) is installed into the cutter bar body (1), the two side cutting edges are adjusted to be symmetrical.

8. The internal thread hole machining method according to claim 6, characterized in that: During the tool adjustment process, it is necessary to ensure that the clearance between the highest point of the outer arc (202) and the bottom hole of the thread is 0.05-0.1 mm.

9. The internal thread hole machining method according to claim 6, characterized in that: When thread cutting, the parts to be processed rotate clockwise.

10. The internal thread hole machining method according to claim 6, characterized in that: After the workpiece is processed, make 1-2 more empty passes.

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