Diesel engine cylinder cover conduit valve seat hole coaxiality measuring device

Abstract

According to the diesel engine cylinder cover conduit valve seat hole coaxiality measuring device, a mandrel is installed in a hollow shaft in an up-down adjustable mode, the inner end portions of a plurality of expansion mechanisms arranged on the hollow shaft correspond to and make contact with the conical wall of the middle-lower portion of the mandrel in position, and the lower end of the hollow shaft is inserted into a cylinder cover conduit hole. The outer end part of the expansion mechanism is ejected outwards to be in close contact with the hole wall of the guide pipe hole of the air cylinder cover or retracts inwards to be separated from the hole wall of the guide pipe hole of the air cylinder cover by adjusting the mandrel, and a lever indicator is rotationally mounted at the upper end of the hollow shaft; and when the measuring head of the lever dial indicator is in contact with the cylinder cover valve seat hole, the detection of the coaxiality of the cylinder cover valve seat hole and the cylinder cover conduit hole is completed by rotating the lever dial indicator. According to the utility model, the positioning gap between the detection tool and the cylinder cover conduit hole in the detection process is eliminated, so that the detection result of the coaxiality of the cylinder cover valve seat hole and the cylinder cover conduit hole is accurate, the operation process is convenient and efficient, the high-precision coaxiality detection is completed on the premise of not influencing the quality of the hole wall, and the reliability is good.

Description

Technical Field

[0001] The utility model belongs to the technical field of diesel engine cylinder head detection, and particularly relates to a device for measuring the coaxiality of a guide tube valve seat hole of a diesel engine cylinder head. Background Art

[0002] The cylinder head is the heart of a diesel engine, and the guide valve seat hole system is one of the key hole systems in the diesel engine cylinder head. The coaxiality of the guide valve seat hole determines the position stability of the valve during operation. If the coaxiality is not high, it will cause cylinder pressure leakage, affecting the output power and fuel economy of the diesel engine, and at the same time cause accelerated wear of the valve and valve seat. Therefore, the shape and position tolerance requirements of the guide valve seat hole in the diesel engine cylinder head are extremely high.

[0003] Generally, there are several methods for measuring the coaxiality of the duct valve seat hole of the cylinder head: 1. Measurement by three-dimensional coordinate measuring machine. Measuring the coaxiality of the duct valve seat hole by three-dimensional coordinate measuring machine has the following disadvantages: ① The measurement cost of using three-dimensional coordinate measuring machine is high, the measurement efficiency is low, and it cannot meet the needs of batch detection; ② The duct valve seat hole of the cylinder head is a large-pitch hole system, which cannot be measured in one direction by ordinary probes. There is a rotation error in the head turning measurement, and the measurement accuracy cannot be guaranteed by using an extended probe; ③ The three-dimensional coordinate measuring room is generally far away from the production line, and workers need to transport the cylinder head to the measuring room, which is labor-intensive; 2. Coaxiality comprehensive plug gauge detection. The following disadvantages: ① The coaxiality comprehensive plug gauge is only suitable for the situation where both measured elements give the maximum physical requirements, and it is not applicable to most cylinder head guide valve seat holes; ② Improper operation of the coaxiality comprehensive plug gauge will scratch the measured hole, affecting product quality; ③ The coaxiality comprehensive plug gauge will wear and deform with frequent use, resulting in incorrect inspection and omission, affecting the product quality judgment result; 3. The detection method of the optional core shaft combined with the dial indicator has the following disadvantages: There is a gap between the core shaft and the guide hole, which leads to an error in the guide hole reference axis, seriously affecting the coaxiality detection accuracy of the valve seat hole; therefore, it is necessary to make improvements. Utility Model Content

[0004] The technical problem solved by the utility model is to provide a coaxiality measuring device for the cylinder head duct valve seat hole of a diesel engine, which eliminates the positioning gap between the inspection fixture and the cylinder head duct hole during the inspection process, has the function of self-aligning the center axis of the cylinder head duct hole, so that the coaxiality inspection results of the cylinder head valve seat hole and the cylinder head duct hole are accurate, has a simple structure, a convenient operation process, and high inspection efficiency, solves the problems existing in traditional measurement methods, completes high-precision coaxiality inspection without affecting the quality of the hole wall, and has good reliability.

[0005] The technical solution adopted by the utility model is as follows: a coaxiality measuring device for a diesel engine cylinder head duct valve seat hole, comprising a core shaft and a hollow shaft, wherein the core shaft is adjustably mounted in the hollow shaft, and the inner ends of a plurality of expansion mechanisms arranged on the hollow shaft correspond to and contact the tapered wall position of the lower middle portion of the core shaft, the lower end of the hollow shaft is inserted into the cylinder head duct hole, and the outer end of the expansion mechanism is pushed outward to closely contact the cylinder head duct hole wall or retracted inward to separate from the cylinder head duct hole wall by adjusting the core shaft, a lever dial indicator is rotatably mounted on the upper end of the hollow shaft, and the coaxiality of the cylinder head valve seat hole and the cylinder head duct hole is detected by rotating the lever dial indicator when the probe of the lever dial indicator contacts the cylinder head valve seat hole.

[0006] In which, the tightening mechanism includes a tightening block, a spring and a stop cover. A plurality of T-shaped holes connected to the inner hole are formed on the outer wall of the middle and lower sections of the hollow shaft, and the stop cover is threadedly fixed to the inside of the large hole at the outer end of the T-shaped hole. The tightening block has a stepped cylindrical structure, and the inner end face of the tightening block is an inclined surface that fits the conical wall. The large diameter end of the tightening block fits into the slot hole of the stop cover, and the small diameter section of the tightening block passes through the stop cover and the small hole at the inner end of the T-shaped hole. The spring is installed between the step surface at the inner end of the tightening block and the stop cover, and under the action of the spring, the inclined surface at the inner end of the tightening block contacts the conical wall. The tightening block is pushed out by the downward-moving core shaft and is in close contact with the cylinder head duct hole.

[0007] Furthermore, a bearing is positioned and installed on the upper end of the hollow shaft, and a table frame for fixing and installing a lever dial indicator is fixed on the outer ring of the bearing.

[0008] Furthermore, the stepped inner hole of the hollow shaft includes a threaded hole at the upper end, a guide hole at the lower end and an equal-diameter hole connecting the threaded hole and the guide hole. The aperture of the guide hole is smaller than the aperture of the equal-diameter hole. The core shaft includes a screw segment at the upper end, a guide segment at the lower end and a through-diameter segment connecting the screw segment and the guide segment into one. The middle and lower sections of the through-diameter segment are provided with two sections of conical walls, and the equal-diameter section shaft wall on the outer periphery of each section of the conical wall is evenly distributed with multiple T-shaped holes. The screw segment is adapted to be connected with the threaded hole, and the through-diameter section and the guide segment are respectively adapted to the equal-diameter hole and the guide hole.

[0009] Furthermore, a hand wheel is fixed to the upper end of the screw segment, which is convenient for rotating the operating core shaft and is located outside the hollow shaft.

[0010] The advantages of this utility model compared with the prior art are:

[0011] 1. This technical solution eliminates the positioning gap between the inspection fixture and the cylinder head guide hole during the inspection process, making the coaxiality inspection results of the cylinder head valve seat hole and the cylinder head guide hole accurate;

[0012] 2. This technical solution includes the expansion mechanism of the expansion block, spring, and cover, which cooperates with the tapered wall in the middle and lower part of the core shaft to enable the structure to self-align the center axis of the cylinder head guide hole, providing conditions for further improving the detection results. The setting of the spring allows the expansion block, which is not squeezed, to contract inward under the action of the spring, thereby easily withdrawing the detection structure;

[0013] 3. This technical solution provides a rotating mounting condition for the lever dial indicator on the hollow shaft by setting a bearing at the upper end of the hollow shaft, thereby quickly measuring the coaxiality of the cylinder head guide valve seat hole by rotating the lever dial indicator;

[0014] 4. This technical solution has a simple structure, convenient operation process, high detection efficiency, solves the problems existing in traditional measurement methods, completes high-precision coaxiality detection without affecting the quality of the hole wall, and has good reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the utility model;

[0016] Figure 2 for Figure 1 A partial enlarged schematic diagram in the middle;

[0017] Figure 3 This is a schematic diagram of the utility model in use. DETAILED DESCRIPTION

[0018] The following is a combination of the embodiments of the present invention Figure 1-3 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0019] It should be noted that, in this document, unless otherwise stated, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate positions or relationships based on those shown in the accompanying drawings. These are intended only to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the elements.

[0021] Diesel engine cylinder head guide valve seat hole coaxiality measuring device, such as Figure 1-3 As shown, it includes a core shaft 1 and a hollow shaft 2, the core shaft 1 is adjustable in the upper and lower positions thereof, and the inner ends of the multiple expansion mechanisms provided on the hollow shaft 2 correspond to and contact the tapered wall 1-1 in the middle and lower part of the core shaft 1, the lower end of the hollow shaft 2 is inserted into the cylinder head conduit hole, and the core shaft 1 is adjusted so that the outer end of the expansion mechanism is pushed outward to closely contact the hole wall of the cylinder head conduit hole 9 or retracted inward to separate from the hole wall of the cylinder head conduit hole 9, and a lever dial indicator 8 is rotatably installed on the upper end of the hollow shaft 2, and when the probe of the lever dial indicator 8 contacts the cylinder head valve seat hole 10, the coaxiality of the cylinder head valve seat hole 10 and the cylinder head conduit hole 9 is detected by rotating the lever dial indicator 8; the above structure eliminates the positioning gap between the inspection tool and the cylinder head conduit hole 9 during the inspection process, so that the coaxiality inspection result of the cylinder head valve seat hole 10 and the cylinder head conduit hole 9 is accurate;

[0022] like Figure 2 As shown, the specific structure of the tightening mechanism is as follows: the tightening mechanism includes a tightening block 3, a spring 4 and a stop cover 5. A plurality of T-shaped holes 2-1 connected to the inner hole are formed on the outer wall of the middle and lower sections of the hollow shaft 2, and the stop cover 5 is threadedly fixed to the inner side of the large hole at the outer end of the T-shaped hole 2-1. The tightening block 3 has a stepped cylindrical structure, and the inner end face of the tightening block 3 is an inclined surface that fits closely with the conical wall 1-1. The large diameter end of the tightening block 3 fits into the slot of the stop cover 5, and the small diameter section of the tightening block 3 passes through the stop cover 5 and the small hole at the inner end of the T-shaped hole 2-1. The spring 4 is sleeved on the inner end platform of the tightening block 3 The step surface and the stop cover 5 are located between the two ends of the expansion block 3, and the inner end inclined surface of the expansion block 3 is brought into contact with the tapered wall 1-1 under the action of the spring 4. The expansion block 3 is ejected by the downward-moving core shaft 1 and is in close contact with the cylinder head conduit hole 9. In the above structure, the expansion mechanism including the expansion block 3, the spring 4 and the stop cover 5 cooperates with the tapered wall 1-1 in the middle and lower part of the core shaft 1, so that the structure has the function of self-aligning the central axis of the cylinder head conduit hole 9, providing conditions for further improving the detection results. The setting of the spring 4 allows the expansion block 3, which is not squeezed, to contract inwardly under the action of the spring 4, thereby easily withdrawing the detection structure.

[0023] The rotary mounting structure of the lever dial indicator 8 on the hollow shaft 2 is as follows: a bearing 6 is positioned and mounted on the upper end of the hollow shaft 2, and a gauge holder 7 for fixing the lever dial indicator 8 is fixed to the outer ring of the bearing 6. In this structure, the bearing 6 provided at the upper end of the hollow shaft 2 provides a rotational mounting condition for the lever dial indicator 8 on the hollow shaft 2, thereby enabling the coaxiality of the cylinder head guide valve seat hole to be quickly measured by rotating the lever dial indicator 8.

[0024] The specific structure of the hollow shaft 2 and the core shaft 1 is as follows: the stepped inner hole of the hollow shaft 2 includes a threaded hole 2-2 at the upper end, a guide hole 2-3 at the lower end and an equal-diameter hole 2-4 connecting the threaded hole 2-2 and the guide hole 2-3, the aperture of the guide hole 2-3 is smaller than the aperture of the equal-diameter hole 2-4, the core shaft 1 includes a screw segment 1-2 at the upper end, a guide segment 1-3 at the lower end and a through-diameter segment 1-4 connecting the screw segment 1-2 and the guide segment 1-3 as one, the middle and lower sections of the through-diameter segment 1-4 are provided with two sections of conical walls 1-1, and the equal-diameter segment 2-4 shaft wall on the outer periphery of each section of the conical wall 1-1 is evenly distributed with multiple T-shaped holes 2-1, the screw segment 1-2 is adapted to be connected with the threaded hole 2-2, and the through-diameter segment 1-4 and the guide segment 1-3 are adapted to be respectively in the equal-diameter hole 2-4 and the guide hole 2-3.

[0025] In order to facilitate the operation of the core shaft 1, a hand wheel 11 is fixed to the upper end of the screw segment 1-2 for facilitating the rotation of the core shaft 1 and is located outside the hollow shaft 2.

[0026] In this structure, the core shaft 1 is located inside the hollow shaft 2, and is matched with two coaxial holes at the upper and lower ends (equal diameter hole 2-4 and guide hole 2-3). The threaded hole 2-2 at the upper end is used for the up and down movement of the core shaft 1. The middle and lower sections of the diameter section 1-4 are provided with two sections of tapered walls 1-1, and the angle of the tapered wall 1-1 is consistent with the angle of the inner inclined surface of the expansion block 3.

[0027] An optical axis is provided at the upper end of the hollow shaft 2, and the optical axis is coaxial with its internal threaded hole 2-2, guide hole 2-3 and equal-diameter hole 2-4. A bearing 6 is provided on the optical axis, and the inner ring of the bearing 6 has an interference fit with it. The outer ring of the bearing 6 is provided with a meter frame 7, and the meter frame 7 is provided with a lever dial indicator 8.

[0028] A large gap is provided between the outer wall of the hollow shaft 2 and the cylinder head conduit hole 9, so that the hollow shaft 2 can be easily inserted into the cylinder head conduit hole 9; three circumferentially evenly distributed expansion mechanisms are provided at two locations on the lower part of the hollow shaft 2.

[0029] Measurement method: During testing, insert the expandable portion of the device into the cylinder head conduit hole 9. Thread core shaft 1 downward into hollow shaft 2. Rotate core shaft 1 so that its downwardly moving tapered wall 1-1 presses the inner inclined surface of expansion block 3 outward, bringing the outer curved surface of expansion block 3 into close contact with cylinder head conduit hole 9. This ensures that core shaft 1 and hollow shaft 2 are centered within cylinder head conduit hole 9. Adjust the probe angle of lever dial indicator 8 so that it contacts cylinder head valve seat hole 10. Then, rotate lever dial indicator 8 one full revolution, observe the pointer movement, and determine whether the coaxiality between cylinder head valve seat hole 10 and cylinder head conduit hole 9 is acceptable based on the reading.

[0030] After the inspection is completed, the core shaft 1 is rotated upward, and the expansion block 3 is contracted inward by the force of the spring 4, so that the structure can be easily pulled out; this measurement method can make the positioning part of the device fit tightly with the cylinder head duct hole and automatically align the center axis of the duct hole.

[0031] In this structure, the core shaft 1 and the hollow shaft 2 are matched through coaxial holes with small gaps at the upper and lower ends, and the inner ring of the bearing 6 is interference fit with the optical axis at the upper end of the hollow shaft 2, thereby ensuring that the main body of the measuring device is highly coaxial; the core shaft 1 is provided with two tapered walls 1-1 in the middle, and the angle of the tapered wall 1-1 is consistent with the angle of the inner bevel of the tightening block 3; the size of the equal-diameter hole 2-4 in the middle of the hollow shaft 2 is larger than the outer circle size of the large end of the tapered wall 1-1 in the middle of the core shaft 1, and the upper end of the hole opening of the lower guide hole 2-3 is chamfered to facilitate the installation of the core shaft 1; the depth of the equal-diameter hole 2-4 in the middle of the hollow shaft 2 is set according to the compression margin of the tightening mechanism; a spring 4 is provided in the middle of the baffle 5 and the tightening block 3. When the core shaft 1 is screwed out upward, the tightening block 3 can be contracted inward by the force of the spring 4, thereby easily withdrawing the inspection fixture.

[0032] This technical solution has a simple structure, convenient operation process, high detection efficiency, solves the problems existing in traditional measurement methods, completes high-precision coaxiality detection without affecting the quality of the hole wall, and has good reliability.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0034] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A device for measuring the coaxiality of a valve seat hole in a cylinder head of a diesel engine, characterized by: The invention comprises a core shaft (1) and a hollow shaft (2), wherein the core shaft (1) is adjustable in position up and down and is installed in the hollow shaft (2), and the inner ends of the multiple expansion mechanisms arranged on the hollow shaft (2) correspond to and contact the tapered wall (1-1) in the middle and lower part of the core shaft (1), and the lower end of the hollow shaft (2) is inserted into the cylinder head conduit hole, and the outer end of the expansion mechanism is pushed outward to closely contact the hole wall of the cylinder head conduit hole (9) or retracted inward to separate from the hole wall of the cylinder head conduit hole (9) by adjusting the core shaft (1). A lever dial indicator (8) is rotatably installed on the upper end of the hollow shaft (2), and when the probe of the lever dial indicator (8) contacts the cylinder head valve seat hole (10), the coaxiality of the cylinder head valve seat hole (10) and the cylinder head conduit hole (9) is detected by rotating the lever dial indicator (8).

2. The diesel engine cylinder head guide valve seat hole coaxiality measuring device according to claim 1, characterized in that: The expansion mechanism comprises an expansion block (3), a spring (4) and a stop cover (5). A plurality of T-shaped holes (2-1) communicating with the inner hole are formed on the outer wall of the middle and lower sections of the hollow shaft (2), and the stop cover (5) is threadedly fixed to the inner side of the large hole at the outer end of the T-shaped hole (2-1). The expansion block (3) is a stepped columnar structure, and the inner end surface of the expansion block (3) is an inclined surface that fits the tapered wall (1-1). The large diameter end of the expansion block (3) is The expansion block (3) is adapted to fit into the slot of the stop cover (5), and the small diameter section of the expansion block (3) passes through the stop cover (5) and the small hole at the inner end of the T-shaped hole (2-1). The spring (4) is set between the inner end step surface of the expansion block (3) and the stop cover (5), and under the action of the spring (4), the inner end inclined surface of the expansion block (3) contacts the tapered wall (1-1). The expansion block (3) is pushed out by the downward moving core shaft (1) and is in close contact with the cylinder head guide tube hole (9).

3. The diesel engine cylinder head guide valve seat hole coaxiality measuring device according to claim 1, characterized in that: A bearing (6) is positioned and installed on the upper end of the hollow shaft (2), and a meter frame (7) for fixing and installing a lever dial indicator (8) is fixed on the outer ring of the bearing (6).

4. The diesel engine cylinder head guide valve seat hole coaxiality measuring device according to claim 1, 2 or 3, characterized in that: The stepped inner hole of the hollow shaft (2) comprises a threaded hole (2-2) at the upper end, a guide hole (2-3) at the lower end, and an equal-diameter hole (2-4) connecting the threaded hole (2-2) and the guide hole (2-3), wherein the diameter of the guide hole (2-3) is smaller than the diameter of the equal-diameter hole (2-4), and the core shaft (1) comprises a screw section (1-2) at the upper end, a guide section (1-3) at the lower end, and a screw section (1-2) and a guide section (1-3) connecting the screw section (1-2) and the guide section (1-3). The through-diameter section (1-4) is connected as one body, wherein the middle and lower sections of the through-diameter section (1-4) are provided with two sections of tapered walls (1-1), and a plurality of T-shaped holes (2-1) are evenly distributed on the circumference of the shaft wall of the equal-diameter section (2-4) on the outer periphery of each section of the tapered wall (1-1), the screw section (1-2) is adapted to be connected with the threaded hole (2-2), and the through-diameter section (1-4) and the guide section (1-3) are adapted to be respectively fitted in the equal-diameter hole (2-4) and the guide hole (2-3).

5. The diesel engine cylinder head guide valve seat hole coaxiality measuring device according to claim 4, characterized in that: A hand wheel (11) is fixed to the upper end of the screw segment (1-2) and is convenient for rotating the core shaft (1) and is located outside the hollow shaft (2).

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