Cold extrusion strengthening tool

Abstract

The invention relates to the field of changing the physical properties of steel through an expansion method, in particular to a cold extrusion strengthening tool. According to the brand-new cold extrusion strengthening tool, the power motor serves as a power source, the rotating action of the output end of the power motor is converted into the linear action of the tail end transmission part through the transmission structure, and the strengthening core rod is driven to act through the tail end transmission part, so that compared with the prior art, a hydraulic pump station, a hydraulic pipeline and the like do not need to be configured; the tool is convenient to carry and use, and pollution is avoided.

Description

Technical Field

[0001] The present invention relates to the field of changing the physical properties of steel by expansion method, and in particular to cold extrusion strengthening tools. Background Art

[0002] In the field of aerospace, the high stress and complex environment that structural parts are subjected to require materials with excellent strength and fatigue life. High-strength materials, such as titanium alloys and high-temperature alloys, are widely used in aerospace structural parts due to their excellent mechanical properties. However, during the operation of these high-strength material components, especially under the action of alternating loads, stress concentration is prone to occur at the aperture orifice, leading to the initiation and expansion of fatigue cracks, which seriously affects the fatigue life of the components. Relevant survey statistics show that about 50% to 90% of fatigue cracks on structural parts in the aerospace field are caused by connection holes.

[0003] Cold extrusion strengthening technology applies pressure to the hole wall to cause it to undergo plastic deformation, thereby introducing residual stress and enhancing fatigue life. For example, a method for strengthening a slotted bushing cold extrusion assembly hole and a matching tooling device disclosed in a Chinese invention patent with application publication number CN114085968A discloses an extrusion gun, which connects an extrusion mandrel that passes through the strengthened hole to the gun head of the extrusion gun. After the extrusion mandrel is pulled through the strengthened hole, the hole wall undergoes plastic deformation, thereby achieving the purpose of strengthening. However, the extrusion gun used therein uses hydraulic power as a driving force to drive the gun head to move forward or backward, and needs to be equipped with a hydraulic pump station and pipelines, which is very inconvenient to carry and use. Summary of the invention

[0004] The purpose of the present invention is to provide a cold extrusion strengthening tool to solve the problem that the existing extrusion gun needs to be equipped with a hydraulic system as a power source, which is inconvenient to carry and use.

[0005] The cold extrusion strengthening tool of the present invention comprises a gun body, which comprises a handle and a gun body. The gun body has an installation inner cavity extending along its length direction, in which a power motor and a transmission structure connected to the output end of the power motor are installed. The power motor and the transmission structure are arranged along the length direction of the gun body, and the end transmission member of the transmission structure has a mandrel interface for connecting a strengthening mandrel, and the transmission structure is a conversion transmission structure for converting the rotational motion of the output end of the power motor into the linear motion of the end transmission member.

[0006] Furthermore, the transmission structure includes a rotating force transmission member rotatably installed in the gun body, the rotating force transmission member is axially fixedly installed in the gun body, the end transmission member and the rotating force transmission member are spirally matched, when the reinforcing core rod and the reinforced hole are pressed tightly, the reinforcing core rod and the end transmission member rely on friction to keep them from rotating with the reinforced hole, the end transmission member and the rotating force transmission member are spirally driven by spiral matching, and the end transmission member pulls the reinforcing core rod to move.

[0007] Furthermore, the end transmission member includes a first force transmission shaft and a second force transmission shaft which are threadedly connected, the first force transmission shaft is screwed together with the rotating force transmission member, and the core rod interface is arranged on the second force transmission shaft.

[0008] Furthermore, the transmission structure also includes a conversion joint with a stop sleeve mounted on the output shaft of the power motor, a rotational stop plug-in installed between the rotating force transmission member and the end of the conversion joint facing away from the power motor, a first rolling bearing is provided between the inner cavity wall of the installation cavity and the outer circumferential surface of one end of the conversion joint close to the rotating force transmission member, and a second rolling bearing is provided between the outer circumferential surface of the end of the rotating force transmission member facing away from the conversion joint and the inner cavity wall of the installation cavity.

[0009] Furthermore, the outer peripheral surface of the conversion joint is a multi-step surface, the rotation transmission member anti-rotation sleeve is mounted on the small diameter section, the first rolling bearing is mounted on the middle diameter section and one end is blocked by the step, and the other end is directly or indirectly blocked by the rotation transmission member, the outer peripheral surface of the rotation transmission member is a step surface, and the second rolling bearing is mounted on the small diameter section, and the small diameter section is also mounted with plane bearings with plane washers arranged axially at intervals, and the front end of the gun body is installed with a bearing end cover at the front port of the inner cavity, and the bearing end cover presses the second rolling bearing and the plane bearing axially on the step of the rotation transmission member.

[0010] Furthermore, the bearing end cover includes a planar cover body portion and an axially extending barrel section, the planar cover body portion is fixedly connected to the gun body, the planar cover body portion blocks the front end surface of the rotating force transmission component, the end transmission component passes through and extends out from the axially extending barrel section, the middle part of the end transmission component has a forward annular step surface, and the front end of the axially extending barrel section has an inner flange that blocks the annular step surface.

[0011] Furthermore, a restraining sleeve is fixedly installed at the front end of the gun body, the restraining sleeve is sleeved on the outside of the axially extending barrel section, and a buffer sleeve is slidably sleeved between the two, the buffer sleeve is configured with a spring to provide it with a forward elastic force, the restraining sleeve blocks the buffer sleeve in the forward direction, and the front end of the terminal transmission part extends from the front end of the buffer sleeve.

[0012] Furthermore, a buffer sleeve is elastically and floatingly installed at the front end of the gun body in the front-to-back direction, the buffer sleeve is provided with a spring providing a forward elastic force thereto, and the front end of the terminal transmission member extends out from the front end of the buffer sleeve.

[0013] Furthermore, a buffer pad is installed on the front end surface of the buffer sleeve.

[0014] Furthermore, a battery and a control module are installed on the handle, and a forward and reverse button for controlling the forward and reverse rotation of the power motor is installed on the handle.

[0015] The present invention provides a new cold extrusion strengthening tool, which uses a power motor as a power source, and converts the rotational motion of the output end of the power motor into a linear motion of the terminal transmission member through a transmission structure, and drives the strengthening core rod to move through the terminal transmission member. Compared with the prior art, there is no need to configure a hydraulic pump station and hydraulic pipelines, etc., and the tool is more convenient to carry and use, and there is no pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the external structure of the first embodiment of the cold extrusion strengthening tool of the present invention when a strengthening mandrel is installed; Figure 2 It is a schematic diagram of the internal structure of the first embodiment of the cold extrusion strengthening tool of the present invention when a strengthening mandrel is installed; Figure 3 This is a schematic diagram of the internal structure of the gun body (with a reinforced core rod installed); Figure 4 for Figure 3 An enlarged view of the structure at the front end of the gun body; Figure 5 Schematic diagram of the structure of the strengthening core rod.

[0017] In the figure: 10, handle; 11, gun body; 110, power motor; 111, mounting frame; 2, bearing end cover; 20, axially extending barrel section; 21, plane cover body part; 22, inner flange of end cover; 3, restraining sleeve; 33, inner flange of sleeve; 4, buffer sleeve; 40, spring; 41, buffer pad; 44, outer flange of sleeve; 50, conversion joint; 51, rotating force transmission member; 52, first force transmission shaft; 53, second force transmission shaft; 60, first rolling bearing; 61, second rolling bearing; 62, plane bearing; 7, control module; 70, forward button; 71, reverse button; 8, battery; 9, strengthening core rod; 90, threaded connection section; 91, extrusion strengthening section. DETAILED DESCRIPTION

[0018] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0019] The cold extrusion strengthening core rod of the present invention adopts a power motor as the power part providing power, designs a new transmission structure to convert the rotational action of the power motor into a linear push-pull action to drive the strengthening core rod to move. Under the premise of being able to provide reliable driving force, the structure of the power part is simplified, and the problem of complicated configuration of the power part and inconvenience in carrying and using due to the need to configure hydraulic pipelines and hydraulic pump stations when using hydraulic telescopic cylinders to drive push-pull actions is eliminated.

[0020] Based on the above concept, various embodiments of cold extrusion strengthening tools are provided below for illustration.

[0021] In a basic embodiment, Figure 1 As shown, the cold extrusion strengthening tool includes a gun body similar to a pistol, the gun body includes a handle 10 and a gun body 11 nearly perpendicular to the handle 10, the handle 10 and the gun body 11 both have a cavity structure, a power motor 110 is fixedly installed in the installation cavity extending along the length direction of the gun body 11 through a mounting frame 111, the rotation output end of the power motor 110 is connected to a transmission structure, the power motor 110 and the transmission structure are arranged along the length direction of the gun body 11, and the terminal transmission member of the transmission structure has a structure for connecting to the gun body 11. Figure 5 The transmission structure of the mandrel interface of the reinforcing mandrel 9 shown is a conversion transmission structure that converts the rotational motion of the output end of the power motor 110 into the linear motion of the terminal transmission member.

[0022] A control module 7 is installed in the inner cavity of the handle 10, and the control module 7 is connected to the power motor 110. The control module 7 is provided with control buttons, including a forward button 70 and a reverse button 71, and the forward and reverse buttons 71 are exposed from the surface of the handle 10 for pressing. A battery 8 for power supply can be installed at the lower end or in the inner cavity of the handle 10. In this way, when performing cold extrusion strengthening work, the cold extrusion strengthening tool and the matching strengthening mandrel 9 can be carried, and the use position is almost unlimited, which is very convenient.

[0023] When the cold extrusion strengthening tool is in use, the force in the length direction of the gun body 11, that is, the axial direction of the power motor 110, that is, the push-pull movement direction of the strengthening mandrel 9 is relatively large. How to stably and reliably convert the rotational power output by the power motor 110 into the push-pull force of the strengthening mandrel 9 is particularly important for the strengthening tool. Based on the above embodiment, the transmission structure is described in detail in the following embodiment.

[0024] In one embodiment, the transmission structure may include a screw nut structure, that is, a rotating screw sleeve connected to the output end of the power motor 110 drives a linear screw rod matched with the rotating screw sleeve to move linearly, and the linear screw rod and the gun body 11 are locked and guided to slide in the axial direction. The linear screw rod serves as the terminal transmission component, and its front end is provided with a core rod interface for connecting to the strengthening core rod 9. In order to reduce the size of the gun body 11 and simplify the matching structure between the gun body 11 and the transmission structure, in a preferred embodiment, as Figure 2-4 As shown, the transmission structure includes a rotating force transmission member 51 rotatably installed in the gun body 11, and the rotating force transmission member 51 is fixedly installed in the gun body 11 relative to the gun body 11 in the axial direction, and the end transmission member and the rotating force transmission member 51 are screw-fitted. Compared with the screw nut structure, the anti-rotation fit between the end transmission member and the gun body 11 is omitted. When the reinforcing mandrel 9 is pressed against the reinforced hole during use, the reinforcing mandrel 9 is kept anti-rotated by friction with the reinforced hole, and the reinforcing mandrel 9 is anti-rotated with the end transmission member. The end transmission member and the rotating force transmission member 51 are screw-fitted to realize screw drive, so that the rotational motion of the rotating force transmission member 51 is converted into the linear motion of the end transmission member, so that the end transmission member pulls the reinforcing mandrel 9 to move.

[0025] The final transmission member can be a shaft structure with a core rod interface at the front end and a threaded mating section at the rear end that is spirally mated with the rotating force transmission member 51. Since the axial force and axial impact on the transmission mechanism are relatively large during use, in order to avoid damage to the spiral mating portion between the final transmission member and the rotating force transmission member 51 and to avoid the difficulty in disassembly due to thread deformation between the two, such as Figure 2-4 In the illustrated embodiment, the final transmission member includes a first force transmission shaft 52 and a second force transmission shaft 53 which are threadedly connected, the first force transmission shaft 52 is threadedly matched with the rotating force transmission member 51, and the mandrel interface is arranged on the second force transmission shaft 53. In this way, adding a threaded connection position and a detachable connection position not only facilitates disassembly, but also can disperse axial impact.

[0026] In one embodiment, the output end of the power motor 110 can be directly connected to the rotating force transmission member 51. Figure 2-3 In the embodiment shown, the transmission structure also includes a conversion joint 50 that is locked and mounted on the output shaft of the power motor 110, a rotation transmission member 51 is locked and inserted into the end of the conversion joint 50 that faces away from the power motor 110, a first rolling bearing 60 is provided between the inner wall of the installation cavity and the outer peripheral surface of the end of the conversion joint 50 that is close to the rotation transmission member 51, and a second rolling bearing 61 is provided between the outer peripheral surface of the end of the rotation transmission member 51 that faces away from the conversion joint 50 and the inner wall of the installation cavity. Figure 2-3It can be seen that the mounting frame 111 is arranged near the output end of the power motor 110, the first rolling bearing 60 is arranged at the end of the conversion joint 50 facing away from the power motor 110, one end of the conversion joint 50 cooperates with the output shaft of the power motor 110, and the other end is supported by the first rolling bearing 60 and the gun body 11 for rotation, which can ensure the stability of the rotation state. For the rotating force transmission member 51, it can ensure the stability of the rotation state by means of the first rolling bearing 60 arranged near one end and the second rolling bearing 61 arranged at the other end.

[0027] Specifically, the outer peripheral surface of the conversion joint 50 is a multi-step surface, the first rolling bearing 60 is mounted on the middle diameter section, one end of the first rolling bearing 60 is blocked by the step on the conversion joint 50, the rotational force transmission member 51 is anti-rotationally mounted on the small diameter section, the rotational force transmission member 51 is blocked at the other end of the first rolling bearing 60 (or a spacer ring is clamped between the rotational force transmission member 51 and the first rolling bearing 60, and the rotational force transmission member 51 blocks the first rolling bearing 60 through the spacer ring), the outer peripheral surface of the rotational force transmission member 51 is a step surface, and the second rolling bearing 61 is mounted on the small diameter section. In order to ensure that the rotating force transmission member 51 can still rotate smoothly when subjected to axial force, a plane bearing 62 with plane washers arranged in an axial direction is also mounted on the small diameter section of the rotating force transmission member 51, and there is a gap between the outer edge of the plane bearing 62 and the gun body 11. The front end of the gun body 11 is installed with a bearing end cover 2 at the front port of the installation cavity, and the bearing end cover 2 axially presses the second rolling bearing 61 and the plane bearing 62 on the step of the rotating force transmission member 51. The bearing end cover 2 also keeps the rotating force transmission member 51 from pressing and stopping the first rolling bearing 60 and the conversion joint 50 backward through the rotating force transmission member 51. When assembling this structure, the components in the installation cavity of the gun body 11 can be assembled in sequence from front to back, which is convenient for disassembly and assembly.

[0028] The bearing end cover 2 can be an annular flat cover, and the end transmission member extends from the annular hole of the annular flat cover. In one embodiment, in order to prevent the end transmission member from being subjected to lateral loads, the bearing end cover 2 includes a planar cover body portion 21 and an axially extending barrel section 20, the planar cover body portion 21 is fixedly connected to the gun body 11, the planar cover body portion 21 blocks the front end surface of the rotating force transmission member 51, and the end transmission member passes through and extends from the axially extending barrel section 20. The middle part of the end transmission member has a forward annular step surface, and the front end of the axially extending barrel section 20 has an end cover inner flange 22 that blocks the annular step surface. The axial tensile resistance of the transmission structure can also be improved by blocking the annular step surface and the end cover inner flange 22.

[0029] like Figure 3As shown, when the terminal transmission component includes a first force transmission shaft 52 and a second force transmission shaft 53 that are threadedly connected, the front end of the first force transmission shaft 52 has a threaded hole, and the rear end of the second force transmission shaft 53 has a threaded shaft. The second force transmission shaft 53 is screwed into the threaded hole of the first force transmission shaft 52, and the front end annular surface of the first force transmission shaft 52 constitutes an annular step surface and blocks the inner flange.

[0030] As mentioned above, the strengthening tool will be subjected to axial impact when in use. In order to avoid damage to the strengthened hole caused by the impact between the tool and the strengthened hole, such as Figure 4 In the embodiment shown, a restraining sleeve 3 is fixedly mounted at the front end of the gun body 11. The restraining sleeve 3 includes a barrel portion and an outer flange at the rear end of the barrel portion. The front end of the barrel portion is provided with a barrel inner flange. The restraining sleeve 3 and the bearing end cover 2 are fixedly connected to the gun body 11 by screws that pass through the two and are screwed into the gun body 11 in sequence. The restraining sleeve 3 is sleeved on the outer side of the axially extending barrel section 20, and a buffer sleeve 4 is slidably sleeved between the two. The rear end of the buffer sleeve 4 has a sleeve outer flange 44, and the sleeve outer flange 44 and the sleeve inner flange 33 are blocked. The buffer sleeve 4 is provided with a spring 40 that provides a forward elastic force thereto. The spring 40 can be arranged between the buffer sleeve 4 and the plane cover portion 21, or between the end cover inner flange 22 as shown in the figure and the front end inverted edge of the buffer sleeve 4. The front end of the end transmission member extends from the front end inverted edge of the buffer sleeve 4.

[0031] Of course, in other embodiments, the buffer sleeve 4 can also be directly installed on the gun body 11. For example, the buffer sleeve 4 is sleeved on the outer side of the gun body 11, and a stopping structure is provided on the gun body 11 to prevent the buffer sleeve 4 from falling off, and a spring 40 is clamped between the buffer sleeve 4 and the bearing end cover 2.

[0032] In addition, in an optimized embodiment, a buffer pad 41 is installed on the front end surface of the buffer sleeve 4. The buffer pad 41 can be made of, for example, a polyurethane pad. The outer edge of the buffer pad 41 is provided with an outer edge extending backward, and is sleeved on the front end of the buffer sleeve 4 through the outer edge.

[0033] When the cold pressurized strengthening tool of the present invention is in use, molybdenum disulfide is coated on the strengthening mandrel 9, the threaded connection section 90 of the strengthening mandrel 9 is passed through the hole to be strengthened and connected to the mandrel interface of the strengthening tool, the strengthening tool is tightened to press the extrusion strengthening section 91 against the edge of the hole to be strengthened, and then the strengthening tool is started. Since the strengthening mandrel 9 is pressed against the edge of the hole to be strengthened, the friction between the two ensures that the strengthening mandrel 9 does not rotate, and the strengthening mandrel 9 can be pulled by the strengthening tool until the extrusion strengthening section 91 is forced through the hole to be strengthened, thereby completing the cold extrusion strengthening of the hole to be strengthened.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. Cold extrusion strengthening tool, characterized by: The invention comprises a gun body, which comprises a handle and a gun body. The gun body has an installation inner cavity extending along its length direction. A power motor and a transmission structure connected to the output end of the power motor are installed in the installation inner cavity. The power motor and the transmission structure are arranged along the length direction of the gun body, and the end transmission part of the transmission structure has a mandrel interface for connecting a reinforcing mandrel. The transmission structure is a conversion transmission structure for converting the rotational motion of the output end of the power motor into the linear motion of the end transmission part.

2. The cold extrusion strengthening tool according to claim 1, characterized in that: The transmission structure includes a rotating force transmission member rotatably installed in the gun body, the rotating force transmission member is axially fixedly installed in the gun body, the end transmission member and the rotating force transmission member are spirally matched, when the strengthening core rod and the strengthened hole are pressed tightly, the strengthening core rod and the end transmission member are kept stationary by friction with the strengthened hole, the end transmission member and the rotating force transmission member are spirally driven by spiral matching, and the end transmission member pulls the strengthening core rod to move.

3. The cold extrusion strengthening tool according to claim 2, characterized in that: The terminal transmission member comprises a first force transmission shaft and a second force transmission shaft which are threadedly connected. The first force transmission shaft is threadedly matched with the rotating force transmission member, and the core rod interface is arranged on the second force transmission shaft.

4. The cold extrusion strengthening tool according to claim 2, characterized in that: The transmission structure also includes a conversion joint with a stop sleeve mounted on the output shaft of the power motor, a rotational force transmission member and an end of the conversion joint facing away from the power motor are rotationally fixed, a first rolling bearing is provided between the inner cavity wall of the installation cavity and the outer circumferential surface of one end of the conversion joint close to the rotational force transmission member, and a second rolling bearing is provided between the outer circumferential surface of the end of the rotational force transmission member facing away from the conversion joint and the inner cavity wall of the installation cavity.

5. The cold extrusion strengthening tool according to claim 4 is characterized in that the conversion The outer peripheral surface of the joint is a multi-step surface, the anti-rotation sleeve of the rotating force transmission part is mounted on the small diameter section, the first rolling bearing is mounted on the middle diameter section and one end is blocked by the step, and the other end is directly or indirectly blocked by the rotating force transmission part, the outer peripheral surface of the rotating force transmission part is a step surface, and the second rolling bearing is mounted on the small diameter section, and the small diameter section is also mounted with plane bearings with plane washers arranged axially at intervals, and the front end of the gun body is installed with a bearing end cover at the front port of the inner cavity, and the bearing end cover presses the second rolling bearing and the plane bearing axially on the step of the rotating force transmission part.

6. The cold extrusion strengthening tool according to claim 5, characterized in that: The bearing end cover includes a planar cover body part and an axially extending barrel section. The planar cover body part is fixedly connected to the gun body, and the planar cover body part blocks the front end surface of the rotating force transmission part. The end transmission part passes through and extends out from the axially extending barrel section. The middle part of the end transmission part has a forward annular step surface, and the front end of the axially extending barrel section has an inner flange that blocks the annular step surface.

7. The cold extrusion strengthening tool according to claim 6, characterized in that: A restraining sleeve is fixedly installed at the front end of the gun body. The restraining sleeve is sleeved on the outside of the axially extending barrel section, and a buffer sleeve is slidably sleeved between the two. The buffer sleeve is equipped with a spring that provides forward elastic force to it. The restraining sleeve stops the buffer sleeve in the forward direction, and the front end of the terminal transmission part extends out from the front end of the buffer sleeve.

8. The cold extrusion strengthening tool according to claim 1, characterized in that: A buffer sleeve is elastically and floatingly installed at the front end of the gun body in the front-back direction. The buffer sleeve is provided with a spring that provides a forward elastic force thereto. The front end of the terminal transmission member extends out from the front end of the buffer sleeve.

9. The cold extrusion strengthening tool according to claim 7 or 8, characterized in that: A buffer pad is installed on the front end surface of the buffer sleeve.

10. The cold extrusion strengthening tool according to any one of claims 1 to 8, characterized in that: A battery and a control module are installed on the handle, and a forward and reverse button for controlling the forward and reverse rotation of the power motor is arranged on the handle.

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