Automatic nut screwing device

Abstract

The invention relates to an automatic nut screwing device which is used for automatically screwing a nut onto a workpiece and comprises a wrench, a jacking air cylinder and a positioning tool, the jacking air cylinder is mechanically connected with the wrench and drives the wrench to do linear motion, and one end of the wrench is provided with a screwing block and can drive the screwing block to do rotary motion; the tightening block is used for positioning one end of the workpiece and driving the workpiece to rotate; the positioning tool comprises a mounting base, a positioning clamping block assembly and a nut positioning assembly, the positioning clamping block assembly is mechanically connected with the mounting base to achieve positioning of a workpiece, and the nut positioning assembly is mechanically connected with the mounting base to achieve positioning of a nut. The automatic nut screwing machine is reasonable in design and simple in structure, the wrench and the air cylinder are used for achieving automatic assembly of a workpiece and a nut, the positioning tool is used for achieving automatic operation of positioning and nut screwing on the nut and the workpiece, the working efficiency is improved, the economical efficiency is good, and the automatic nut screwing machine is suitable for automatic and intelligent batch production.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical assembly equipment, in particular to an automatic nut tightening device. Background Art

[0002] In the manufacturing and assembly of automobiles and their parts, a large amount of repetitive assembly work is often required on the workpieces. With the improvement of automation and intelligence of the production line, some assembly processes need to be automated. At present, some parts of the assembly of the rear suspension rear control arm assembly of the automobile are still assembled by manual tightening, which has low work efficiency. In order to meet the needs of mass production, it is necessary to develop an automatic nut tightening device for the rear suspension rear control arm assembly to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide an automatic nut tightening device, which realizes the automatic assembly of workpieces and nuts, improves work efficiency, has a high degree of automation and intelligence, and is suitable for automated mass production.

[0004] To achieve the above-mentioned purpose, the present invention provides an automatic nut tightening device for automatically tightening a nut onto a workpiece, comprising: a wrench, a tightening cylinder, and a positioning tool. The tightening cylinder is mechanically connected to the wrench and drives the wrench to perform linear motion. A tightening block is provided at one end of the wrench and can drive the tightening block to perform rotational motion. The tightening block is used to position one end of the workpiece and drive the workpiece to perform rotational motion. The positioning tool comprises: a mounting seat, at least one positioning block assembly, and a nut positioning assembly. The positioning block assembly is mechanically connected to the mounting seat to achieve positioning of the workpiece, and the nut positioning assembly is mechanically connected to the mounting seat to achieve positioning of the nut.

[0005] Furthermore, the nut positioning assembly includes: a first positioning block and a second positioning block, wherein the first positioning block and the second positioning block are respectively mechanically connected to the mounting seat and symmetrically arranged and adapted to the shape of the nut to achieve the positioning of the nut.

[0006] Furthermore, the first positioning block is provided with a first slot and a first guide surface, and the second positioning block is provided with a second slot and a second guide surface; the shapes of the first slot and the second slot are adapted to the nut.

[0007] Furthermore, the positioning tool also includes: a first sensor, a second sensor, a third sensor, and a connecting block. The first sensor is arranged on one side of the positioning block assembly to realize workpiece state detection, and the second sensor is arranged on one side of the nut positioning assembly to realize nut state detection; the third sensor is mechanically connected to the nut positioning assembly through the connecting block to realize workpiece motion state detection.

[0008] Preferably, the first sensor, the second sensor and the third sensor are proximity switches.

[0009] Furthermore, it also includes: a clamping cylinder, which is provided with a pressure rod and can drive the pressure rod to move to achieve positioning and clamping of the workpiece.

[0010] Optionally, the wrench is driven by pneumatic or electric means.

[0011] The present invention relates to an automatic nut tightening device, and the beneficial effects are as follows: the automatic nut tightening device of the present invention has a reasonable design and a simple structure, realizes automatic threaded connection between a workpiece and a nut by using the coordinated action of a wrench and two cylinders, and realizes good positioning of the nut and the workpiece by using a positioning tool, thereby realizing the automated operation of tightening the nut, improving work efficiency, saving manpower and material resources, having good economy, and being suitable for automated and intelligent mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0013] Figure 1 A schematic diagram of the three-dimensional structure of an automatic nut tightening device provided by an embodiment of the present invention;

[0014] Figure 2 A top view of an automatic nut tightening device provided by an embodiment of the present invention;

[0015] Figure 3 A schematic diagram of the three-dimensional structure of a positioning tool provided in an embodiment of the present invention;

[0016] Figure 4 A schematic diagram of the three-dimensional structure of a nut positioning assembly provided in an embodiment of the present invention;

[0017] Figure 5 A top view of a nut positioning assembly provided in an embodiment of the present invention;

[0018] Figure 6 A schematic diagram of the three-dimensional structure of a nut positioning assembly with a workpiece provided in an embodiment of the present invention.

[0019] In the figure:

[0020] 1. Wrench; 11. Tightening block; 2. Tightening cylinder; 21. Connecting seat; 3. Positioning tool; 31. Mounting seat; 32. Positioning block assembly; 321. First block; 322. Second block; 33. Nut positioning assembly; 331. First positioning block; 3311. First slot; 3312. First guide surface; 332. Second positioning block; 3321. Second slot; 3322. Second guide surface; 34. First sensor; 35. Second sensor; 36. Third sensor; 37. Connecting block; 4. Tightening cylinder; 41. Pressure rod; 5. Rear suspension rear control arm. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. It should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", "fourth", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0024] An automatic nut tightening device according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0025] Example

[0026] Figure 1A schematic diagram of the three-dimensional structure of an automatic nut tightening device provided by an embodiment of the present invention is shown; Figure 2 A top view of an automatic nut tightening device provided by an embodiment of the present invention is shown; Figure 3 A schematic diagram of the three-dimensional structure of a positioning tool provided in an embodiment of the present invention is shown; Figure 4 A schematic diagram of the three-dimensional structure of a nut positioning assembly provided in an embodiment of the present invention is shown; Figure 5 A top view of a nut positioning assembly provided by an embodiment of the present invention is shown; Figure 6 The 3D structural diagram of the nut positioning assembly with a workpiece provided by an embodiment of the present invention is shown. Figures 1 to 6 As shown, an automatic nut tightening device provided by an embodiment of the present invention is mainly used for automatically tightening a nut onto a workpiece. Different from the prior art, the automatic nut tightening device provided by an embodiment of the present invention comprises: a wrench 1, a tightening cylinder 2, and a positioning tool 3, wherein the tightening cylinder 2 is mechanically connected to the wrench 1 and drives the wrench 1 to perform linear motion. In this embodiment, a connecting seat 21 is arranged on the piston rod of the tightening cylinder 2, the wrench 1 is mechanically connected to the connecting seat 21, and the tightening cylinder 2 can be arranged on a workbench and remain relatively fixed. In this way, the connecting seat 21 can be controlled to perform linear motion by controlling the air path of the tightening cylinder 2, thereby driving the wrench 1 to perform linear motion, thereby achieving the purpose of controlling the wrench 1 to enter and exit the workstation and push the workpiece to perform linear motion, which is convenient for loading and unloading and assembling workpieces. One end of the wrench 1 is provided with a tightening block 11 and can drive the tightening block 11 to rotate. The tightening block 11 is used to position one end of the workpiece and drive the workpiece to rotate. The rotating shaft of the wrench 1 is mechanically connected with the tightening block 11, so that the tightening block 11 rotates synchronously with the rotating shaft of the wrench 1. The tightening block 11 is clamped and positioned with one end of the workpiece. The workpiece in the embodiment of the present invention is taken as an example of the rear suspension rear control arm 5. The shape of the rear suspension rear control arm 5 is as follows: Figure 6 As shown, one end of the rear suspension rear control arm 5 is a cylinder, and the tightening block 11 is provided with a square cavity. The cylinder at one end of the rear suspension rear control arm 5 can be inserted into the square cavity of the tightening block 11. The height of the square cavity of the tightening block 11 is adapted to the height of the cylinder of the rear suspension rear control arm 5. In this way, when the tightening block 11 is driven by the wrench 1 to rotate, the workpiece, that is, the rear suspension rear control arm 5, is synchronously driven to rotate, thereby realizing the threaded connection between the rear suspension rear control arm 5 and the nut. In an automatic nut tightening device provided by an embodiment of the present invention, the driving mode of the wrench 1 is one of pneumatic and electric, and the rotation control of the wrench 1 can be realized by connecting the wrench 1 to an external control system. Preferably, the wrench 1 is a pneumatic wrench, mainly utilizing the characteristics of fast response speed and good economy of the pneumatic wrench; of course, the wrench 1 can also be electric, mainly utilizing the characteristics of high control accuracy of the electric mode; as for which driving mode the wrench 1 specifically uses, it can be selected according to the needs of the user.

[0027] The positioning fixture 3 in the embodiment of the present invention comprises: a mounting seat 31, at least one positioning block assembly 32, and a nut positioning assembly 33, wherein the positioning block assembly 32 is mechanically connected to the mounting seat 31 to realize the positioning of the workpiece, and generally at least two positioning block assemblies 32 are used here, which are respectively used to locate and clamp different positions of the workpiece, so that the positioning of the workpiece is accurate and reliable, and an opening is provided in the middle of the positioning block assembly 32 for placing the workpiece, and the width of the opening is adapted to the diameter of the corresponding position of the workpiece; it is worth noting that the positioning block assembly 32 here can be in an integrated form or a split form, as long as the positioning of the workpiece can be realized; Figure 3 The positioning block assembly 32 shown in the figure is a split structure, where the positioning block assembly 32 is composed of two parts, a first block 321 and a second block 322, which are respectively located on both sides of the workpiece, and the positioning of the workpiece is completed by relying on the space between the first block 321 and the second block 322. When the positioning block assembly 32 is a split structure, the space between the first block 321 and the second block 322 can be adjusted to adapt to workpieces of different diameters, and the versatility is better; it is worth noting that when the positioning block assembly 32 is an integrated form, the corresponding first block 321 and the second block 322 can be combined and set into one part, and only the corresponding opening position needs to be set for placing the workpiece. The nut positioning assembly 33 is mechanically connected to the mounting seat 31 to realize the positioning of the nut, and the nut can be placed on the nut positioning assembly 33 by manual or robot automatic grasping, and the nut position positioning is completed by the nut positioning assembly 33.

[0028] In an automatic nut tightening device provided by an embodiment of the present invention, more specifically, a nut positioning assembly 33 includes: a first positioning block 331 and a second positioning block 332; specifically, the first positioning block 331 and the second positioning block 332 are respectively mechanically connected to the mounting seat 31 and symmetrically arranged and adapted to the shape of the nut for positioning the nut. More specifically, the first positioning block 331 is provided with a first slot 3311 and a first guide surface 3312, and the second positioning block 332 is provided with a second slot 3321 and a second guide surface 3322; wherein the shapes of the first slot 3311 and the second slot 3321 are adapted to the nut, Figure 5The figure shows the shape of a nut that matches the rear control arm 5 of the rear suspension. The first slot 3311 and the second slot 3321 can locate the edge or convex edge on the clamping nut; the first guide surface 3312 and the second guide surface 3322 are in a slope shape, and the angle between the first guide surface 3312 and the second guide surface 3322 is a "V"-shaped opening, which is convenient for the smooth placement and posture adjustment of the nut. The first guide surface 3312 and the second guide surface 3322 play a guiding role in the placement of the nut; it is worth mentioning that the nut here is generally a hexagonal nut or a square nut, so that the nut can be clamped by using the plane on the outer contour of the nut through the first positioning block 331 and the second positioning block 332, and the spacing between the first positioning block 331 and the second positioning block 332 is adapted to the shape of the nut and can clamp the corresponding contact surface on the nut to prevent the nut from rotating synchronously with the rotation of the workpiece.

[0029] In an automatic nut tightening device provided by an embodiment of the present invention, the positioning tool 3 also includes: a first sensor 34, a second sensor 35, a third sensor 36, and a connecting block 37, wherein the first sensor 34 is arranged on one side of a positioning block assembly 32 for realizing workpiece state detection, and the first sensor 34 can be arranged on one of the first block 321 and the second block 322. When the workpiece is placed on the positioning block assembly 32, the first sensor 34 can detect the corresponding signal and send the signal to an external control system, and the control system controls the rotation of the wrench 1 according to the control logic; wherein the second sensor 35 is arranged on one side of the nut positioning assembly 33 for realizing nut state detection, and the second sensor 35 can be arranged in the first positioning block 331 and the second positioning block 332 On one of them, by judging whether there is a nut, a corresponding signal can be detected and sent to the control system; and the third sensor 36 is mechanically connected to one of the first positioning block 331 and the second positioning block 332 in the nut positioning assembly 33 through the connecting block 37 to realize the detection of the motion state of the workpiece. When the wrench 1 drives the workpiece to rotate, the tightening cylinder 2 drives the wrench 1 to move linearly synchronously. At this time, the workpiece rotates and moves linearly at the same time. When the workpiece and the nut are screwed to the set position, one end of the workpiece passes through the nut and extends a certain length. When one end of the workpiece approaches the third sensor 36, the third sensor 36 detects that the workpiece has reached the set position, so that the third sensor 36 sends a signal to the control system, and the start and stop action of the wrench 1 is controlled by the control system. By arranging the first sensor 34, the second sensor 35, and the third sensor 36 on the positioning fixture 3, the motion logic of each component in the automatic nut tightening device can be coordinated and controlled, which greatly improves the automation and intelligence of the automatic nut tightening device and improves reliability and safety. In an automatic nut tightening device provided by an embodiment of the present invention, preferably, the first sensor 34, the second sensor 35, and the third sensor 36 are proximity switches, which mainly utilizes the characteristics of proximity switches that are widely used, economical, and highly reliable; of course, the first sensor 34, the second sensor 35, and the third sensor 36 may also use other types of sensors, including but not limited to proximity switches, as long as they can realize position detection of the workpiece or the nut.

[0030] An automatic nut tightening device provided in an embodiment of the present invention also includes: a clamping cylinder 4, wherein the clamping cylinder 4 is provided with a pressure rod 41 and can drive the pressure rod 41 to move to achieve positioning and clamping of the workpiece, the pressure rod 41 is mechanically connected to the piston rod in the clamping cylinder 4, and the pressure rod 41 drives the piston rod through the clamping cylinder 4 to drive the pressure rod 41 to achieve clamping and loosening operations on the workpiece, and the reliability and accuracy of the automatic nut tightening device are improved by clamping and positioning the workpiece, and the phenomenon of one end of the workpiece being lifted up, which leads to inaccurate docking position between the workpiece and the nut, is effectively prevented.

[0031] Compared with the prior art, the automatic nut tightening device of the present invention has a reasonable design and a simple structure. Automatic threaded connection between a workpiece and a nut is achieved by using a wrench 1 and the coordinated action of two cylinders. Good positioning of the nut and the workpiece is achieved by using a positioning tool 3, thereby realizing automated operation of tightening the nut, improving work efficiency, saving manpower and material resources, having good economy, and being suitable for automated and intelligent mass production.

[0032] There are a few points to note:

[0033] (1) Unless otherwise defined, in the embodiments of the present invention and the accompanying drawings, the same reference numerals represent the same meanings.

[0034] (2) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention, and other structures may refer to the general design.

[0035] (3) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, some structures in the drawings may be enlarged or reduced, that is, these drawings are not drawn according to the actual scale.

[0036] (4) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0037] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An automatic nut tightening device, used for automatically tightening a nut onto a workpiece, characterized in that: include: A wrench (1), a tightening cylinder (2), and a positioning tool (3), wherein the tightening cylinder (2) is mechanically connected to the wrench (1) and drives the wrench (1) to perform linear motion, a tightening block (11) is provided at one end of the wrench (1) and can drive the tightening block (11) to perform rotational motion, and the tightening block (11) is used to position one end of a workpiece and drive the workpiece to perform rotational motion; The positioning tool (3) comprises: a mounting seat (31), at least one positioning block assembly (32), and a nut positioning assembly (33); the positioning block assembly (32) is mechanically connected to the mounting seat (31) to achieve positioning of the workpiece; and the nut positioning assembly (33) is mechanically connected to the mounting seat (31) to achieve positioning of the nut.

2. The automatic nut tightening device according to claim 1, characterized in that: The nut positioning assembly (33) comprises: a first positioning block (331) and a second positioning block (332); the first positioning block (331) and the second positioning block (332) are respectively mechanically connected to the mounting seat (31) and symmetrically arranged and adapted to the shape of the nut for positioning the nut.

3. The automatic nut tightening device according to claim 2, characterized in that: The first positioning block (331) is provided with a first clamping groove (3311) and a first guide surface (3312), and the second positioning block (332) is provided with a second clamping groove (3321) and a second guide surface (3322); the shapes of the first clamping groove (3311) and the second clamping groove (3321) are adapted to the nut.

4. The automatic nut tightening device according to claim 1, characterized in that: The positioning tool (3) further comprises: a first sensor (34), a second sensor (35), a third sensor (36), and a connecting block (37); the first sensor (34) is arranged on one side of the positioning block assembly (32) for realizing workpiece state detection; the second sensor (35) is arranged on one side of the nut positioning assembly (33) for realizing nut state detection; the third sensor (36) is mechanically connected to the nut positioning assembly (33) via the connecting block (37) for realizing workpiece motion state detection.

5. The automatic nut tightening device according to claim 4, characterized in that: The first sensor (34), the second sensor (35), and the third sensor (36) are proximity switches.

6. The automatic nut tightening device according to any one of claims 1 to 5, characterized in that: Also includes: A clamping cylinder (4) is provided with a pressure rod (41) and can drive the pressure rod (41) to move so as to achieve positioning and clamping of a workpiece.

7. The automatic nut tightening device according to claim 6, characterized in that: The wrench (1) is driven in one of pneumatic and electric manners.

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