A tensioning mandrel for diesel engine cylinder detection

Abstract

This utility model discloses a tensioning mandrel for diesel engine cylinder block testing, including a shaft body with a receiving groove inside. A tensioning assembly is housed within the receiving groove, and the tensioning assembly includes a mounting groove. Two sets of movable blocks are symmetrically slidably arranged within the mounting groove. Each set of movable blocks is hinged with four sets of connecting rods, the ends of which are hinged to the connecting blocks. An arc-shaped plate is connected to the ends of the connecting blocks. A sliding groove is formed on the outer surface of the shaft body, and a drive assembly is housed within the receiving groove. A limiting assembly is provided on the shaft body. This utility model achieves rapid, accurate, and non-destructive positioning and fixing during diesel engine cylinder block testing. When the drive assembly is rotated, the two sets of movable blocks move synchronously towards each other. The hinged connecting rods precisely convert the axial force into radial thrust of the connecting blocks, thereby pushing the arc-shaped plate to move smoothly outward, effectively eliminating the fit clearance between the mandrel and the cylinder bore, and providing an extremely stable and reliable reference positioning for subsequent precision testing.

Description

Technical Field

[0001] This utility model relates to the field of diesel engine technology, specifically to a tensioning mandrel for testing diesel engine cylinder blocks. Background Technology

[0002] In utility model patent application CN213147615U, published on May 7, 2021, entitled "A Tensioning Mandrel for Diesel Engine Cylinder Block Inspection," this utility model discloses a tensioning mandrel for diesel engine cylinder block inspection, belonging to the field of diesel engine cylinder block inspection technology. The key technical point is that the tensioning mandrel for diesel engine cylinder block inspection includes a mandrel body, with a positioning flange fixed at the bottom of the mandrel body. The positioning flange has a first groove formed inside through a one-time machining process. A left ring is built into one side of the inside of the groove, and a right ring is built into the other side of the inside of the first groove. In this utility model, by setting guide rods, steel balls, short rods and springs, a set of guide rods presses a set of short rods inward after being pulled, so that the steel balls overcome the rebound effect of the spring and achieve outward tension. At this time, the mandrel locates the center reference line of the hole to be tested by the expansion and centering of the two cross-section steel balls, thereby completing the entire detection operation. Compared with the previous card strip detection method, the size limitation of the entire detection operation is smaller, and the entire detection operation is also very convenient.

[0003] In the aforementioned patents or prior art, precise inspection of key internal holes is crucial during the manufacturing and repair of diesel engine cylinder blocks. Traditional inspection fixtures, due to their simple structure, suffer from insufficient positioning stability, which not only causes drift in the measurement reference but also directly leads to inaccurate inspection data for dimensional and positional tolerances such as hole diameter and roundness. Utility Model Content

[0004] The purpose of this invention is to provide a tensioning mandrel for testing diesel engine cylinder blocks, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a tensioning mandrel for testing a diesel engine cylinder block, comprising a shaft body, a receiving groove provided within the shaft body, a tensioning assembly provided within the receiving groove, the tensioning assembly including an installation groove formed on the inner wall of the receiving groove, two sets of movable blocks symmetrically slidably arranged within the installation groove, each set of movable blocks having four sets of connecting rods hinged to it, the ends of the four sets of connecting rods on the same movable block being respectively hinged to the four sets of connecting blocks, the ends of the two symmetrically arranged sets of connecting blocks fitting together, and the ends of the two fitting sets of connecting blocks being fixedly connected to an arc-shaped plate, four sets of sliding grooves communicating with the receiving groove on the outer surface of the shaft body, the sliding grooves slidingly engaging with the connecting blocks, a driving assembly for driving the two sets of movable blocks to move synchronously in opposite directions or in opposite directions within the receiving groove, and a limiting assembly provided on the shaft body.

[0006] Furthermore, the drive assembly includes a slot at one end of the shaft, a rotating rod rotatably mounted on one end of the inner wall of the receiving slot, the other end of the rotating rod extending into the slot, and a bidirectional thread on the outer surface of the portion of the rotating rod located in the mounting slot. Two sets of symmetrically arranged movable blocks are threadedly connected to the bidirectional threaded section of the rotating rod.

[0007] Furthermore, a handle is rotatably provided inside the slot, and the end of the handle is fixedly connected to the rotating rod.

[0008] Furthermore, a tapered groove is provided at the top of the shaft for docking with the operating equipment.

[0009] Furthermore, the end of the handle is provided with a docking groove for connecting tools.

[0010] Furthermore, the limiting assembly includes four sets of guide rods fixed to the outside of the shaft, and the four sets of guide rods are slidably connected to the arc-shaped plate.

[0011] Furthermore, the ends of the four sets of guide rods furthest from the shaft are all fixedly connected to a mounting ring.

[0012] Compared with the prior art, the beneficial effects of this utility model are: the tensioning mandrel for testing diesel engine cylinder blocks is reasonable and has the following advantages: (1) The tensioning mandrel design achieves rapid, accurate and non-destructive positioning and fixing during the testing of diesel engine cylinder blocks through a mechanical linkage structure. When the drive assembly is rotated, the two sets of moving blocks move synchronously towards each other. The axial force is accurately converted into the radial thrust of the connecting block through the hinged connecting rod, thereby pushing the arc plate to move outward smoothly. This design ensures that the four arc plates can contact the inner wall of the engine cylinder evenly and synchronously and apply pressure to form a full-circumferential, high-rigidity support. Its beneficial effect is that it can effectively eliminate the fit gap between the mandrel and the cylinder bore, providing an extremely stable and reliable reference positioning for subsequent precision testing. This not only greatly improves the accuracy and repeatability of the test data, but also avoids measurement errors caused by jig shaking or skew. It is especially suitable for engine manufacturing and testing processes with stringent positioning accuracy requirements. (2) The tensioning mandrel greatly enhances the overall structural rigidity and motion stability through the limiting and guiding components, thereby ensuring the accuracy of the final test results. Through the sliding cooperation of the connecting block and the four sets of sliding grooves on the shaft, the movement trajectory of the connecting block and the arc plate it fixes is ensured, which fundamentally prevents the arc plate from rotating circumferentially or moving axially during expansion or contraction, and ensures that the direction of the tensioning force is always perpendicular to the shaft center. The limiting components further constrain the degree of freedom, ensuring that the four arc plates can maintain extremely high synchronicity and flatness during expansion, avoiding swaying caused by gaps in individual connecting parts or deformation under force, significantly improving the bending and torsional deformation resistance of the front end of the shaft, preventing the shaft itself from undergoing elastic deformation, and maintaining the stability of the mandrel reference axis. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the shaft of this utility model; Figure 3 This is a structural schematic diagram of the cross-section of the shaft of this utility model; Figure 4 This is a schematic diagram of the overall cross-section of the present invention; Figure 5 This is a schematic diagram of the forward structure of the drive component of this utility model; Figure 6 This is a schematic diagram of the reverse structure of the drive component of this utility model; Figure 7 This is a schematic diagram of the structure of the arc-shaped plate of this utility model.

[0014] In the diagram: 100, shaft; 101, receiving groove; 102, mounting groove; 103, slot; 104, handle; 105, rotating rod; 106, movable block; 107, connecting rod; 108, connecting block; 109, arc plate; 110, sliding groove; 111, tapered groove; 112, mating groove; 200, mounting ring; 201, guide rod. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1-7 The present invention provides a technical solution as follows: Example 1: A tensioning mandrel for testing diesel engine cylinder blocks includes a shaft 100 with a receiving groove 101 inside. A tensioning assembly is provided within the receiving groove 101. The tensioning assembly includes a mounting groove 102 formed on the inner wall of the receiving groove 101. Two sets of movable blocks 106 are symmetrically slidably arranged within the mounting groove 102. Each set of movable blocks 106 is hinged with four sets of connecting rods 107. The ends of the four sets of connecting rods 107 on the same movable block 106 are respectively connected to four sets of... The connecting blocks 108 are hinged, and the ends of two sets of symmetrically arranged connecting blocks 108 are attached to each other. The ends of the two sets of attached connecting blocks 108 are fixedly connected to an arc plate 109. The outer surface of the shaft 100 is provided with four sets of sliding grooves 110 that communicate with the receiving groove 101. The sliding grooves 110 are slidably engaged with the connecting blocks 108. The receiving groove 101 is provided with a driving component that drives the two sets of movable blocks 106 to move synchronously in opposite directions or in opposite directions. The shaft 100 is provided with a limiting component.

[0017] The drive assembly includes a slot 103 at one end of the shaft 100. A rotating rod 105 is rotatably provided at one end of the inner wall of the receiving groove 101. The other end of the rotating rod 105 extends into the slot 103. The portion of the rotating rod 105 located in the mounting groove 102 has a bidirectional thread on its outer surface. Two sets of symmetrically arranged movable blocks 106 are threadedly connected to the bidirectional threaded section of the rotating rod 105.

[0018] A handle 104 is rotatably provided inside the slot 103, and the end of the handle 104 is fixedly connected to the rotating rod 105.

[0019] The top end of the shaft 100 is provided with a tapered groove 111 for docking with the operating equipment.

[0020] The end of the handle 104 is provided with a docking groove 112 for connecting tools.

[0021] The limiting assembly includes four sets of guide rods 201 fixed on the outside of the shaft 100, and the four sets of guide rods 201 are slidably connected to the arc plate 109.

[0022] The four sets of guide rods 201 are all fixedly connected to a mounting ring 200 at the ends away from the shaft 100.

[0023] Working Principle: Initially, the two sets of movable blocks 106 are far apart in the mounting groove 102. At this time, through the hinge of the connecting rod 107 with the movable blocks 106 and the connecting blocks 108, the four sets of connecting blocks 108 drive the arc plate 109 to a retracted state, minimizing the outer diameter of the entire tensioning mandrel, making it easy to insert into the hole to be inspected in the engine block. The operator uses a tool inserted into the docking groove 112 to rotate the handle 104, thereby driving the rotating rod 105 to rotate. Since the rotating rod 105 has a bidirectional thread, and the two sets of movable blocks 106 are threadedly connected to it, when the rotating rod 105 rotates, it drives the two sets of movable blocks 106 to move towards each other in the mounting groove 102. The towards-each-other movement of the movable blocks 106 pushes the four sets of connecting rods 107 that are hinged to them. The other end of the connecting rod 107 is hinged to the connecting block 108, and the connecting block 108 is restricted in the slide groove 110 of the shaft 100, and can only move radially. Therefore, the connecting rod 107 transforms the axial opposing movement of the movable blocks 106 into the radial outward movement of the connecting blocks 108. The two symmetrically arranged connecting blocks 108 together press against an arc-shaped plate 109, causing the four arc-shaped plates 109 to move radially outward synchronously. The arc-shaped plates 109 press against the inner wall of the engine cylinder block, thus firmly fixing the entire mandrel within the cylinder bore, providing a stable reference for subsequent inspection operations such as bore diameter measurement and geometric tolerance inspection. During this process, the guide rod 201, fixed to the outside of the shaft 100, passes through the arc-shaped plate 109, ensuring that the arc-shaped plate 109 only makes smooth radial movement without deflection. The mounting ring 200 at the top serves as overall reinforcement and guidance. After the operation is completed, the handle 104 is rotated in the opposite direction using a tool, causing the rotating rod 105 to rotate in the opposite direction, driving the two sets of movable blocks 106 to move in opposite directions. By pulling the connecting rod 107, the connecting block 108 and the arc plate 109 retract radially inward along the slide groove 110 and the guide rod 201, disengaging from contact with the inner wall of the cylinder, and the mandrel can be easily removed.

[0024] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A tensioning mandrel for testing diesel engine cylinder blocks, comprising a shaft (100), characterized in that: The shaft (100) has a receiving groove (101) inside, and a tensioning assembly is provided in the receiving groove (101). The tensioning assembly includes a mounting groove (102) on the inner wall of the receiving groove (101). Two sets of movable blocks (106) are symmetrically slidably arranged in the mounting groove (102). Each set of movable blocks (106) is hinged with four sets of connecting rods (107). The ends of the four sets of connecting rods (107) on the same movable block (106) are respectively hinged to four sets of connecting blocks (108), symmetrically. The ends of the two sets of connecting blocks (108) are fitted together, and the ends of the two sets of connecting blocks (108) are fixedly connected to an arc plate (109). The outer surface of the shaft (100) is provided with four sets of sliding grooves (110) that communicate with the receiving groove (101). The sliding grooves (110) are slidably engaged with the connecting blocks (108). The receiving groove (101) is provided with a driving component that drives the two sets of movable blocks (106) to move synchronously towards each other or away from each other. The shaft (100) is provided with a limiting component.

2. The tensioning mandrel for testing a diesel engine cylinder block according to claim 1, characterized in that: The drive assembly includes a slot (103) at one end of the shaft (100), a rotating rod (105) is rotatably provided at one end of the inner wall of the receiving groove (101), the other end of the rotating rod (105) extends into the slot (103), the outer surface of the portion of the rotating rod (105) located in the mounting groove (102) is provided with a bidirectional thread, and two sets of symmetrically arranged movable blocks (106) are threadedly connected to the bidirectional threaded section of the rotating rod (105).

3. A tensioning mandrel for testing a diesel engine cylinder block according to claim 2, characterized in that: A handle (104) is rotatably provided inside the slot (103), and the end of the handle (104) is fixedly connected to the rotating rod (105).

4. A tensioning mandrel for testing a diesel engine cylinder block according to claim 1, characterized in that: The top end of the shaft (100) is provided with a tapered groove (111) for docking with the operating equipment.

5. A tensioning mandrel for testing a diesel engine cylinder block according to claim 3, characterized in that: The end of the handle (104) is provided with a docking groove (112) for connecting tools.

6. A tensioning mandrel for testing a diesel engine cylinder block according to claim 1, characterized in that: The limiting assembly includes four sets of guide rods (201) fixed on the outside of the shaft (100), and the four sets of guide rods (201) are slidably connected to the arc plate (109).

7. A tensioning mandrel for testing a diesel engine cylinder block according to claim 6, characterized in that: The four sets of guide rods (201) are all fixedly connected to a mounting ring (200) at the ends away from the shaft (100).

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