A piston crown detection fixture

Abstract

The utility model discloses a piston top detection clamp, including base, support, main part, end face positioning ring, clamping assembly, angle positioning assembly and pneumatic control assembly. Steel piston top is positioned through the stop opening formed by the combination of the outer circle and top surface and main part, end face positioning ring, and is restricted angular degree of freedom through angle positioning assembly, and then is pneumatic three -point clamping by clamping assembly, thereby realizes quick, steady clamping. The utility model can guarantee that the repeat positioning accuracy is less than 0.01, has the advantages such as high detection efficiency, high positioning accuracy, compact structure, reliable pressure -loss protection, is applicable to the mass detection of unmanned plane engine steel piston top.

Description

Technical Field

[0001] This utility model relates to the field of fixture technology, and in particular to a piston top detection fixture. Background Technology

[0002] Existing methods for inspecting steel piston tops typically rely on simple V-blocks for auxiliary clamping and positioning. However, since the outer circular surface of the piston top is usually curved in the longitudinal direction, it is prone to skew when placed in the V-groove, leading to inconsistent selection of workpiece references. This results in large overall coordinate system fitting errors and significant deviations between the inspection results and the true values.

[0003] Furthermore, existing methods rely primarily on manual operation for circumferential angle positioning, resulting in poor repeatability and a high risk of misjudgment. During the automatic coordinate measuring machine (CMM) scaffolding process, excessive workpiece skew can lead to program errors, detection failures, and even measurement path interference, causing probe damage or workpiece displacement, severely impacting detection efficiency and reliability.

[0004] In summary, existing detection clamping methods suffer from poor positioning accuracy, poor repeatability, low efficiency, and large errors. There is an urgent need for a fixture that can ensure rapid and stable clamping of the steel piston top and improve detection accuracy. Utility Model Content

[0005] The purpose of this invention is to provide a piston top inspection fixture that enables rapid and reliable clamping of steel piston tops, significantly improving positioning accuracy and inspection efficiency, and is suitable for large-volume inspection scenarios.

[0006] This utility model is achieved by the following technical solution: a piston top detection fixture, characterized in that it includes a base, a bracket, a main body, an end face positioning ring, a clamping assembly, an angle positioning assembly, and a pneumatic control assembly. The fixture is installed as a whole on the worktable of a coordinate measuring machine and is used to position and clamp the top of a steel piston.

[0007] Furthermore, the base is provided with a mounting bottom surface and a connecting bolt hole for positioning and fixing with the worktable of the coordinate measuring machine, and the base is provided with a bracket positioning surface, a bracket positioning surface, and a bracket connecting bolt hole for assembling with the bracket.

[0008] Furthermore, the bracket is provided with a fourth mounting reference surface, a fifth mounting reference surface, a third mounting bolt hole, a first connecting threaded hole, and a first positioning pin hole. The bracket is fixed to the base by bolts and positioned by the first positioning pin hole cooperating with the positioning pin hole of the main body.

[0009] Furthermore, the main body is provided with a clamping component mounting groove 1, on which multiple clamping components are installed to achieve multi-point clamping of the top surface of the steel piston; the main body is provided with a positioning hole 1 in the middle for mounting the outer circle of the top of the steel piston, and the positioning hole 1 is divided into multiple notches 3 by positioning points for probe avoidance.

[0010] Furthermore, the end face positioning ring is connected to the connecting bolt hole five of the main body through threaded hole one, and its end face mates with the end face of the main body; the end face positioning ring is provided with multiple end face positioning points four, which abut against the top surface of the steel piston top, and is provided with a notch one, which corresponds to the notch three of the main body, so that the probe can enter.

[0011] Furthermore, the clamping assembly includes a cylinder, a cylinder connecting plate, a cylinder piston rod, a Y-shaped connector, a hinge, a pressure rod, and a clamping screw. The cylinder piston rod pushes the Y-shaped connector to rotate the pressure rod, thereby driving the clamping screw to clamp or release the top of the steel piston.

[0012] Furthermore, the angle positioning component includes an angle positioning body, a cylindrical positioning pin, and at least two positioning flat pins. The cylindrical positioning pin is inserted into the angle positioning groove of the main body, and the positioning flat pin is inserted into the positioning hole of the top of the steel piston to achieve angular positioning.

[0013] Furthermore, the pneumatic control assembly includes a manual valve, an induction check valve, and an air pipe. The manual valve is used to control the action of the clamping assembly, and the induction check valve is used to maintain the state of the clamping assembly when the air source is depressurized.

[0014] The piston top detection fixture described in this utility model has the following advantages: This utility model uses a combination of outer circle, end face and positioning hole for positioning, which restricts the six degrees of freedom of the workpiece, resulting in high positioning accuracy and repeatability accuracy that can be controlled within 0.01. This invention achieves fast and stable clamping through three-point pneumatic clamping, significantly improving clamping efficiency and making it suitable for batch testing on production lines. This invention does not have any obstruction structure at the workpiece end face and outer circle positioning point, so the coordinate measuring machine probe can collect measurement points without obstruction, avoiding the obstruction problem of traditional fixtures; This utility model is equipped with a gas source pressure loss protection function. When the gas source pressure is reduced or interrupted, the clamping component can still maintain its original state to prevent the workpiece from falling or the probe from being damaged. Compared with traditional V-block positioning, this invention reduces the process of repeated alignment, avoids detection errors caused by skewness, and improves detection accuracy and reliability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 An exploded view of a piston top detection fixture structure; Figure 2 This is a schematic diagram of the base; Figure 3 This is a schematic diagram of the support frame; Figure 4 This is a schematic diagram of the main body; Figure 5 Schematic diagram of the end face positioning ring; Figure 6 This is a schematic diagram of the clamping assembly; Figure 7 Schematic diagram of the angle positioning component; Figure 8 This is a schematic diagram of the pneumatic control components; In the diagram, 1-base; 1.1-mounting bottom surface one; 1.2-connecting bolt hole one; 1.3-bracket positioning surface two; 1.4-bracket positioning surface three; 1.5-bracket connecting bolt hole two; 2-bracket; 2.1-mounting reference surface four; 2.2-mounting reference surface five; 2.3-mounting bolt hole three; 2.4-connecting threaded hole one; 2.5-locating pin hole one; 2.6-connecting bolt hole four; 2.7-clamping component mounting clearance groove one; 3-main body; 3.1-connecting threaded hole two; 3.2-connecting threaded hole three; 3.3-locating pin hole two; 3.4-locating pin hole three; 3.5-clamping component mounting groove one; 3.6-locating hole one; 3.7-locating point; 3.8-notch three; 3.9-angle positioning groove one; 3. 10-Connecting bolt hole five; 4-End face positioning ring; 4.1-Threaded hole one; 4.3-End face positioning point four; 4.4-Notch one; 5-Clamping assembly; 5.1-Cylinder; 5.2-Cylinder connecting plate; 5.3-Cylinder piston rod; 5.4-Hinge shaft one; 5.5-Y-joint; 5.6-Hinge shaft two; 5.7-Hinge; 5.8-Hinge shaft three; 5.9-Pressure rod; 5.10-Pressure screw; 5.11-Screw; 5.12-Screw; 6-Angle positioning assembly; 6.1-Cylindrical positioning pin; 6.2-Angle positioning body; 6.3-Positioning flat pin one; 6.4-Positioning flat pin two; 7-Pneumatic control assembly; 7.1-Manual valve; 7.2-Induction check valve; 7.3-Air pipe; 8-Steel piston top. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example

[0019] like Figure 1 As shown, this embodiment provides a piston top inspection fixture, including a base 1, a bracket 2, a main body 3, an end face positioning ring 4, a clamping assembly 5, an angle positioning assembly 6, and a pneumatic control assembly 7. The fixture is mounted on the worktable of a coordinate measuring machine for high-precision positioning and clamping of the steel piston top 8 to meet batch inspection requirements.

[0020] The base 1 serves as the basic component of the fixture. Its lower part is provided with a mounting surface 1.1 for positioning with the worktable of the coordinate measuring machine and for fastening through the connecting bolt hole 1.2. On it are formed a bracket positioning surface 1.3, a bracket positioning surface 1.4, and a bracket connecting bolt hole 1.5 for assembly with the bracket 2.

[0021] The bracket 2 mates with the positioning surfaces 1.3 and 1.4 of the base 1 via mounting reference surfaces 2.1 and 2.2, and is fixed to the base 1 via mounting bolt holes 2.3 and threaded holes 2.4. The bracket 2 also has a positioning pin hole 2.5 for mates with the positioning pin hole of the main body 3; a connecting bolt hole 2.6 for screwing and fixing to the main body 3; and a clamping assembly mounting clearance groove 2.7 to provide installation space for the clamping assembly 5.

[0022] The main body 3 is fixed to the bracket 2 via connecting threaded holes 3.1 and 3.2. Positioning pin holes 3.3 and 3.4 engage with positioning pin holes 2.5 on the bracket 2, and cylindrical pins are installed to limit the relative position of the main body 3 and the bracket 2, ensuring positional accuracy. The main body 3 has three clamping component mounting slots 3.5, each for mounting three sets of clamping components 5, achieving three-point clamping of the steel piston top 8 end face.

[0023] The main body 3 has a positioning hole 3.6 in the middle for installing the outer circle of the steel piston top 8. The hole is divided into four sections by four positioning points 3.7, forming a notch 3.8, so that the probe can smoothly enter the sampling point. The main body 3 also has an angle positioning groove 3.9 for the cylindrical positioning pin 6.1 of the angle positioning component 6 to be inserted to achieve angular positioning.

[0024] The end face positioning ring 4 is fixed to the connecting bolt hole 3.10 of the main body 3 through the threaded hole 4.1, and its end face mates with the end face of the main body 3. Four end face positioning points 4.3 are provided on the ring body, which abut against the top surface of the steel piston top 8 to further restrict the workpiece's degree of freedom; at the same time, four notches 4.4 are provided, corresponding to the notches 3.8 of the main body 3, to provide clearance space for the probe.

[0025] The clamping assembly 5 is installed in slot 3.5 of the main body 3. It includes a cylinder 5.1, a cylinder connecting plate 5.2, a cylinder piston rod 5.3, a Y-shaped connector 5.5, a hinge 5.7, a pressure rod 5.9, and a clamping screw 5.10. During operation, the cylinder piston rod 5.3 pushes the Y-shaped connector 5.5 axially, causing the pressure rod 5.9 to rotate around the hinge, thus clamping or releasing the clamping screw 5.10 against the end face of the steel piston top 8. The three sets of clamping assemblies 5 are evenly distributed circumferentially to ensure balanced force on the end face. Cylinder 5.1 is fixed to cylinder connecting plate 5.2 by screw 5.11. Cylinder piston rod 5.3 on cylinder 5.1 is equipped with Y-shaped connector 5.5. Y-shaped connector 5.5 is connected to pressure rod 5.9 through hinge shaft 2 5.6 to form a rotating pair. Pressure rod 5.9 is connected to hinge 5.7 through hinge shaft 3 5.8 to form a rotating pair. Hinge 5.7 is connected to cylinder connecting plate 5.2 through hinge shaft 1 5.4 to form a rotating pair. Clamping screw 5.10 is threaded on pressure rod 5.9. When cylinder piston rod 5.3 moves axially, it pushes Y-shaped connector 5.5 to move axially, causing pressure rod 5.9 to rotate forward and backward around hinge shaft 3 5.8, thereby clamping or loosening steel piston top 8.

[0026] The angle positioning component 6 includes an angle positioning body 6.2, a cylindrical positioning pin 6.1, and positioning flat pins 6.3 and 6.4. During clamping, the cylindrical positioning pin 6.1 is inserted into the angle positioning groove 3.9 of the main body 3, and the positioning flat pins 6.3 and 6.4 are inserted into the positioning holes of the steel piston top 8, thereby limiting the angle direction of the workpiece. After clamping, this component can be removed without affecting the inspection.

[0027] The pneumatic control assembly 7 includes a manual valve 7.1, an induction check valve 7.2, and an air pipe 7.3. The manual valve 7.1 is a five-port, three-position, centrally closed type used to control the cylinder's movement; the induction check valve 7.2 is used to maintain the cylinder's state when the air source loses pressure, preventing the workpiece from falling; the air pipe 7.3 and the standard pipe connector form a complete air circuit to control the clamping action of the clamping assembly 5.

[0028] During use, the steel piston top 8 is first placed within the stop formed by the main body 3 and the end face positioning ring 4, with its outer circle and top surface serving as reference surfaces to restrict five degrees of freedom. Then, the sixth degree of freedom is restricted via the angle positioning component 6. Next, the manual valve 7.1 is operated to activate the clamping component 5, pressing the workpiece end face to complete the clamping. After clamping, the angle positioning component 6 is removed, and inspection can then be performed. After inspection, the manual valve 7.1 is operated again to release the clamping component 5, allowing the workpiece to be removed.

[0029] This embodiment achieves rapid and stable workpiece clamping through combined positioning of the outer circle, end face, and positioning holes, along with pneumatic three-point clamping, with repeatability controlled within 0.01. The workpiece's outer circle and end face are fully exposed, allowing for unobstructed inspection by the coordinate measuring machine's probe. The fixture also features air pressure loss protection to prevent workpiece drop or probe damage. Compared to traditional V-block clamping, this embodiment significantly improves inspection efficiency and reliability, making it suitable for mass production line inspections.

[0030] The above embodiments describe the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Modifications and variations made by those skilled in the art without departing from the spirit and scope of this utility model should be protected within the scope of the appended claims.

Claims

1. A piston top detection fixture, characterized in that, The fixture includes a base (1), a bracket (2), a main body (3), an end face positioning ring (4), a clamping assembly (5), an angle positioning assembly (6), and a pneumatic control assembly (7). The fixture is installed on the worktable of a coordinate measuring machine and is used to position and clamp the steel piston top (8).

2. The piston top detection fixture according to claim 1, characterized in that, The base (1) is provided with a mounting bottom surface (1.1) and a connecting bolt hole (1.2) for positioning and fixing with the worktable of the coordinate measuring machine. The base (1) is provided with a bracket positioning surface (1.3), a bracket positioning surface (1.4) and a bracket connecting bolt hole (1.5) for assembling with the bracket (2).

3. A piston top detection fixture according to claim 1, characterized in that, The bracket (2) is provided with mounting reference surface four (2.1), mounting reference surface five (2.2), mounting bolt hole three (2.3), connecting thread hole one (2.4) and positioning pin hole one (2.5). The bracket (2) is fixed to the base (1) by bolts, and is positioned by the positioning pin hole one (2.5) cooperating with the positioning pin hole of the main body (3).

4. A piston top detection fixture according to claim 1, characterized in that, The main body (3) is provided with a clamping component mounting groove (3.5) and multiple clamping components (5) are installed to achieve multi-point clamping of the end face of the steel piston top (8); the main body (3) is provided with a positioning hole (3.6) in the middle for installing the outer circle of the steel piston top (8), and the positioning hole (3.6) is divided by the positioning point (3.7) to form multiple notches (3.8) for probe avoidance.

5. A piston top detection fixture according to claim 4, characterized in that, The end face positioning ring (4) is connected to the connecting bolt hole five (3.10) of the main body (3) through the threaded hole one (4.1), and its end face is matched with the end face of the main body (3); the end face positioning ring (4) is provided with multiple end face positioning points four (4.3), which abut against the top surface of the steel piston top (8), and is provided with notch one (4.4), which corresponds to notch three (3.8) of the main body (3) so that the probe can enter.

6. A piston top detection fixture according to claim 1, characterized in that, The clamping assembly (5) includes a cylinder (5.1), a cylinder connecting plate (5.2), a cylinder piston rod (5.3), a Y-shaped connector (5.5), a hinge (5.7), a pressure rod (5.9), and a clamping screw (5.10). The cylinder piston rod (5.3) pushes the Y-shaped connector (5.5) to drive the pressure rod (5.9) to rotate, thereby driving the clamping screw (5.10) to clamp or loosen the steel piston top (8).

7. A piston top detection fixture according to claim 4, characterized in that, The angle positioning component (6) includes an angle positioning body (6.2), a cylindrical positioning pin (6.1), and at least two positioning flat pins. The cylindrical positioning pin (6.1) is inserted into the angle positioning groove (3.9) of the main body (3), and the positioning flat pin is inserted into the positioning hole of the steel piston top (8) to achieve angular positioning.

8. A piston top detection fixture according to claim 1, characterized in that, The pneumatic control assembly (7) includes a manual valve (7.1), an induction check valve (7.2), and an air pipe (7.3). The manual valve (7.1) is used to control the action of the clamping assembly (5), and the induction check valve (7.2) is used to maintain the state of the clamping assembly (5) when the air source is depressurized.

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