Bolt stress extraction joint

Abstract

The invention discloses a bolt stress extraction connector which comprises a protective sleeve shell, a movable ejector pin structure and a dustproof cap. The protective sleeve shell is used for sleeving the head of the test bolt to protect the test piece on the head of the bolt; the movable thimble structure is used for moving upwards to be in contact with the head of the test bolt to form joint signal communication, and the movable thimble structure is arranged at the lower part of the protective sleeve shell in an up-and-down moving manner; the dustproof cap is detachably installed at the lower end of the protective sleeve shell, so that the protective sleeve shell forms a closed cavity structure. Broken stones can be effectively prevented from splashing to the ceramic plate of the special bolt in the whole vehicle durability road test process, and the ceramic plate is prevented from being broken or falling off; the head of the special bolt can be effectively prevented from being rusted in the whole vehicle durability road test process; the glue joint failure of the glue joint ceramic chip at the head part of the special bolt when meeting water in the road test in the whole vehicle durability road test process can be effectively prevented; bolt axial force measurement interruption and accuracy in the whole vehicle durability road test process can be effectively prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile testing, in particular to a bolt stress extraction joint. Background Art

[0002] Automotive threaded connections are widely used in vehicle manufacturing due to their advantages such as simple assembly, reliable performance, economy, and reproducible disassembly. Currently, threaded connections are mostly used in the assembly and connection of automotive chassis structures. In vehicle durability road testing, measuring the axial force of bolts is a key step in ensuring the reliability of the connection during long-term use. The main purpose of the measurement is to:

[0003] ① Ensure that the bolts maintain appropriate pre-tightening force during long-term use to prevent loosening or breakage;

[0004] ② Evaluate the possibility of bolt loosening or fatigue failure caused by vibration, impact and temperature changes during vehicle operation;

[0005] ③ Ensure that the bolts maintain sufficient strength and durability under various working conditions;

[0006] ④ Discover potential problems in advance, avoid major failures caused by bolt failure, and reduce maintenance costs and accident risks.

[0007] To determine the actual axial force of threaded fasteners after assembly, many manufacturers currently use ultrasonically engineered bolts mounted on endurance vehicles for axial force testing. These bolts (test bolts) require the coating on the bolt head to be ground away, followed by the attachment of a piezoelectric ceramic patch. During subsequent vehicle road tests, the bolt axial force can be regularly tested to determine the actual force.

[0008] However, the road conditions of the vehicle durability road test are diverse. During the durability road test, the special bolts in the chassis are affected by water and gravel collisions, which can cause the piezoelectric ceramic patches to break and fall off, and the bolt head surface to rust, which in turn leads to the failure of the bolt axial force test. The main problems are as follows:

[0009] 1. During the road test, gravel flew and hit the piezoelectric ceramics of the special bolts, causing the ceramics to break or fall off;

[0010] 2. During the road test, the head of the special bolt was corroded, causing the piezoelectric ceramic to fall off or fail;

[0011] 3. During the road test, the vehicle encountered water, which caused the bonding between the piezoelectric ceramic and the bolt head to fail and the ceramic piece to fall off.

[0012] For example, patent CN222479181U discloses an anti-corrosion device for open-hole bolts, comprising: a connected plate and a bolt body disposed within the connected plate; a mounting bracket, the mounting bracket being located outside the bolt body, the lower side of which being fixedly connected to a second sealing ring, the second sealing ring being arranged concentrically; a sealing plate, the sealing plate being located inside the fixing ring, the outer side of which being fixedly connected to a first sealing ring, the first sealing ring being tightly fitted to the fixing ring; and a fastener, the fastener being threadedly connected to the lower end of the bolt body, the upper side of which being fixedly mounted to a third sealing ring, and the outer side of which being tightly fitted to a cable tie. Most bolts on a car chassis have their ends exposed, and this device has a complex structure and cannot be directly fixed to the ends of the bolts. Summary of the Invention

[0013] In view of the shortcomings of the existing technology, the present invention provides a bolt stress extraction joint, which can effectively protect the test bolt head and is easy to operate.

[0014] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0015] The bolt stress extraction joint includes a protective sleeve, a movable ejector pin structure and a dust cap;

[0016] The protective sleeve is used to cover the head of the test bolt to protect the test piece on the bolt head;

[0017] The movable ejector pin structure is used to move upward to contact the test bolt head to form a joint signal connection. The movable ejector pin structure can move up and down and is arranged at the lower part of the protective shell;

[0018] The dust cap is detachably mounted on the lower end of the protective shell, so that the protective shell forms a closed cavity structure.

[0019] Further or preferred:

[0020] The protective sleeve is a sleeve structure adapted to the head of the test bolt.

[0021] A strong magnetic flange for adsorbing on the head of the test bolt is fixed on the upper port of the protective shell.

[0022] The strong magnetic flange is an annular piece and is fixed to the upper end surface of the protective shell by strong glue.

[0023] An annular groove is provided on the upper end surface of the protective shell, and the strong magnetic flange is fixed in the annular groove.

[0024] The protective shell and the dust cap are both made of plastic, and the ejector pin of the movable ejector pin structure is made of steel.

[0025] The lower end of the protective shell is provided with a hollow connector, the outer edge of the connector is provided with a thread, and the dust cap is fixed on the connector through the thread structure.

[0026] The movable ejector structure includes an ejector body and an ejector limiting slider. The lower part of the protective shell is provided with a through hole for the ejector body to pass through. The ejector limiting slider is located in the connector and is arranged corresponding to the lower end of the ejector body.

[0027] An ejector spring is provided above the ejector limiting slider in the connector.

[0028] The ejector limiting slider is a plastic or rubber part, and a movable cavity is provided inside the ejector limiting slider. The lower end head of the ejector body is movably located in the movable cavity, and the lower end of the lower end head is provided with an external joint part that can extend from the bottom of the movable cavity.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The bolt stress extraction joint has a reasonable structural design, which can effectively prevent gravel from splashing onto the ceramic piece of the special bolt during the vehicle durability road test, thereby avoiding the ceramic piece from breaking or falling off; it can effectively prevent the special bolt head from rusting during the vehicle durability road test; it can effectively prevent the bonding failure of the bonded ceramic piece on the special bolt head when encountering water during the road test; it can effectively prevent the interruption and accuracy of the bolt axial force measurement during the vehicle durability road test; and the structure is convenient to position on the test bolt head, the test operation is simple, and the structure is simple and the cost is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following is a brief description of the contents and symbols in the drawings of this specification:

[0032] Figure 1 This is a schematic diagram of the extraction joint decomposition of the present invention.

[0033] Figure 2 Schematic diagram of the extraction joint structure of the present invention.

[0034] Figure 3 This is a schematic diagram of the slider and ejector pin moving upward together according to the present invention.

[0035] Figure 4 Schematic diagram of the height difference between the ejector slider and the ejector limiter of the present invention.

[0036] In the picture:

[0037] 1. Strong magnetic flange, 2. Protective cover, 3. Ejector spring, 4. Ejector body, 5. Ejector limit slider, 6. Dustproof nut. DETAILED DESCRIPTION

[0038] Although the present invention is shown and described herein with reference to specific embodiments, it is not intended that the invention be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims without departing from the present invention. In the accompanying drawings, the same item numbers refer to the same elements.

[0039] Various terms are used throughout this disclosure to describe the physical shape or arrangement of features. Many of these terms are used to describe features that conform to a cylindrical or generally cylindrical geometry with the feature as the radius and a central axis perpendicular to the radius. Unless a different meaning is specified, the terms are given the following meanings. The terms "longitudinal," "longitudinal," "axial," and "axially" refer to a direction, dimension, or orientation that is parallel to the central axis. The terms "radial" and "radially" refer to a direction, dimension, or orientation that is perpendicular to the central axis. The terms "inward" and "inwardly" refer to a direction, dimension, or orientation extending in a radial direction toward the central axis. The terms "outward" and "outwardly" refer to a direction, dimension, or orientation extending in a radial direction away from the central axis.

[0040] In the specification, relative terms such as "horizontal," "vertical," "upward," "downward," "top," and "bottom," and their derivatives (e.g., "horizontal," "downward," "upward," etc.) should be interpreted as referring to the direction being described or shown in the drawings being discussed. These relative terms are for convenience of description and are generally not intended to require a particular orientation.

[0041] The specific implementation of the present invention will be further explained in detail below through description of embodiments with reference to the accompanying drawings.

[0042] like Figures 1 to 4 As shown, this bolt stress extraction joint features corrosion resistance. It includes a protective sleeve 2, a movable ejector pin structure, and a dust cap. Both the protective sleeve and the dust cap are plastic. The protective sleeve 2 is installed over the test bolt head, with the dust cap attached to its lower end. Together, they form a protective structure for the bolt head, effectively preventing debris from splashing onto the ceramic disc of the custom bolt during vehicle endurance road testing, preventing the disc from breaking or falling off.

[0043] The protective sleeve 2 is used to be sleeved on the head of the test bolt to protect the test piece on the bolt head; the movable ejector pin structure is used to move upward to contact the head of the test bolt to form a joint signal connection, and the movable ejector pin structure can be moved up and down and is arranged at the lower part of the protective sleeve; the dust cap is detachably installed at the lower end of the protective sleeve, so that the protective sleeve forms a closed cavity structure.

[0044] The bolt stress extraction joint of the present invention has a reasonable structural design. The protective shell and the dust cap cooperate to form a protective structure. The protective structure wraps around the test bolt head to provide protection, thereby effectively protecting the measuring bolt and the test ceramic piece provided on the test bolt head.

[0045] The following protection effects can be achieved by using the protection structure of the present invention:

[0046] 1. It can effectively prevent gravel from splashing onto the ceramic pieces of the special bolts during the vehicle durability road test, thus preventing the ceramic pieces from breaking or falling off;

[0047] 2. It can effectively prevent the rust of the special bolt heads during the vehicle durability road test; it can effectively prevent the bonding failure of the ceramic pieces bonded to the special bolt heads when exposed to water during the vehicle durability road test;

[0048] 3. It can effectively prevent the interruption and accuracy of bolt axial force measurement during the vehicle durability road test;

[0049] 4. The structure is convenient to locate on the head of the test bolt, the test operation is simple, the structure is simple and the cost is relatively low.

[0050] Preferred structure:

[0051] The protective shell 2 and the dust cap are both made of plastic, and the ejector pin of the movable ejector pin structure is made of steel. The plastic protective shell and dust cap are not easily corroded or rusted. When the dust cap is opened, the ejector pin structure of the steel part can realize data connection. The structure is simple and easy to use and operate.

[0052] The protective sleeve 2 is a sleeve structure that is compatible with the test bolt head. The groove of the protective sleeve is a hexagonal groove that matches the hexagonal structure of the test bolt head. The protective sleeve is a plastic sleeve structure. The groove of the protective sleeve can be interference fit with the side of the bolt head, and the structure is compact.

[0053] A strong magnetic flange 1 is fixed to the upper end of the protective sleeve 2, designed to attach to the test bolt head. This annular flange is bonded to the upper end of the protective sleeve with strong adhesive. The protective sleeve fits over the bolt head and is held in place by the strong magnetic force of the flange, resulting in a simple, stable, and reliable structure.

[0054] Furthermore, an annular groove is provided on the upper end surface of the protective shell, and the strong magnetic flange is fixed in the annular groove, which has a compact structure and is stable and reliable. Alternatively, one side of the strong magnetic flange is integrally injection-molded on the end surface of the port of the protective shell, which has a more reliable structure.

[0055] The lower end of the protective sleeve is equipped with a hollow connector with threads on the outer edge. The dust cap is fixed to the connector through the threads. The protective sleeve and connector are injection molded as a whole. The connector is an integral part of the protective sleeve, which is stable and reliable.

[0056] The connector is a small cylindrical structure with an external thread on the outer edge of the connector. The dust cap is a plastic dust nut 6 with an internal thread matching the external thread. The dust nut is installed through the threaded structure, and the installation and disassembly operations are simple.

[0057] Furthermore, an annular rib is provided on the outer edge of the connecting head, and a sealing ring is provided on the corresponding annular rib on the connecting head. When the dust cap is screwed and installed, the upper end of the dust cap contacts and squeezes the sealing ring, which effectively improves the protection effect of the test bolt head.

[0058] The movable ejector structure includes an ejector body 4 and an ejector limiting slider 5. A through hole for the ejector body to pass through is provided at the lower part of the protective shell. The ejector limiting slider is located in the connector corresponding to the lower end of the ejector body. An ejector spring 3 is provided above the ejector limiting slider in the connector.

[0059] The ejector limiting slider 5 is a plastic or rubber part. A movable cavity is provided inside the ejector limiting slider. The lower end head of the ejector body is movably located in the movable cavity. The lower end of the lower end head is provided with an external joint part that can extend from the bottom of the movable cavity.

[0060] After the dustproof nut 6 is installed, there is a gap between the inner wall of the dustproof nut and the ejector limit slider and the external joint part at the lower end of the ejector body, which will not affect the ejector body structure; during the parking test, the dustproof nut is rotated down and the ejector body is moved upward, and the upper end of the ejector body contacts the test piece on the bolt head to form a data connection; through the setting of the ejector spring, if there is no upward external force acting on the ejector structure, under the action of the downward force of the spring, the ejector structure is prevented from moving upward and contacting the test piece during driving, thereby avoiding damage to the test piece caused by impact.

[0061] The anti-corrosion stress extraction joint of the bolt of the present invention is installed on the special bolt in the assembled state and undergoes a durability road test of the whole vehicle. It can protect the ceramic patch on the head of the special bolt, prevent damage caused by stone impact and vibration shedding that may occur during the durability road test, and protect the surface of the special bolt head, thereby ensuring the accuracy and effectiveness of the bolt axial force measurement during the durability road test of the whole vehicle.

[0062] The strong magnetic flange of the present invention is bonded to the upper end of the hard plastic protective sleeve by strong glue; the protective sleeve and the ejector slider are clearance-matched to ensure the fitting clearance of the ejector in the protective sleeve; a spring is provided at the lower end of the protective sleeve to act on the ejector limit to prevent the upper end of the ejector from impacting the test ceramic sheet; the protective sleeve and the dustproof nut are screwed together by threads.

[0063] Working principle of the present invention:

[0064] By using materials with strong magnetic properties, the bolt flange surfaces are completely adsorbed and adhered to each other, ensuring that they do not fall off during the vehicle's endurance road test.

[0065] The protective shell and the dustproof nut are screwed together through threads to prevent dust;

[0066] The slider limiter can be moved upward as a whole slider. When conducting a durability road test, the dust nut can be unscrewed and the slider limiter can be moved upward;

[0067] The steel ejector pin and the slider begin to move upward together, causing the ejector pin to contact the top of the bolt, and the sensing joint signal is connected at the same time.

[0068] The above is only an illustration of a preferred embodiment of the present invention. The above technical features can be arbitrarily combined to form multiple embodiments of the present invention.

[0069] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A bolt stress extraction joint, characterized in that: include: A protective sleeve is used to cover the head of the test bolt to protect the test piece on the bolt head; A movable ejector pin structure is used to move upward to contact the test bolt head to form a joint signal connection. The movable ejector pin structure can move up and down and is arranged at the lower part of the protective shell; The dust cap is detachably mounted on the lower end of the protective shell, so that the protective shell forms a closed cavity structure.

2. The bolt stress extraction joint according to claim 1, characterized in that: The protective sleeve is a sleeve structure adapted to the head of the test bolt.

3. The bolt stress extraction joint according to claim 2, characterized in that: A strong magnetic flange for adsorbing on the head of the test bolt is fixed on the upper port of the protective shell.

4. The bolt stress extraction joint according to claim 3, characterized in that: The strong magnetic flange is an annular piece and is fixed to the upper end surface of the protective shell by strong glue.

5. The bolt stress extraction joint according to claim 4, characterized in that: An annular groove is provided on the upper end surface of the protective shell, and the strong magnetic flange is fixed in the annular groove.

6. The bolt stress extraction joint according to claim 1, characterized in that: The protective shell and the dust cap are both made of plastic, and the ejector pin of the movable ejector pin structure is made of steel.

7. The bolt stress extraction joint according to claim 1, characterized in that: The lower end of the protective shell is provided with a hollow connector, the outer edge of the connector is provided with a thread, and the dust cap is fixed on the connector through the thread structure.

8. The bolt stress extraction joint according to claim 7, characterized in that: The movable ejector structure includes an ejector body and an ejector limiting slider. The lower part of the protective shell is provided with a through hole for the ejector body to pass through. The ejector limiting slider is located in the connector and is arranged corresponding to the lower end of the ejector body.

9. The bolt stress extraction joint according to claim 8, characterized in that: An ejector spring is provided above the ejector limiting slider in the connector.

10. The bolt stress extraction joint according to claim 8, characterized in that: The ejector limiting slider is a plastic or rubber part, and a movable cavity is provided inside the ejector limiting slider. The lower end head of the ejector body is movably located in the movable cavity, and the lower end of the lower end head is provided with an external joint part that can extend from the bottom of the movable cavity.

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