Diesel engine camshaft gear timing mark gauge

Abstract

A diesel engine camshaft gear timing mark testing fixture comprises a testing fixture body and a mandrel, the mandrel is transversely installed in a central hole of the testing fixture body, the testing fixture body is fixedly connected with the mandrel, and one end of the mandrel on the same side with the testing surface of the testing fixture body is a structure matched with the central hole of the camshaft gear. A clamp body pin hole corresponding to a gear pin hole of the camshaft gear is formed in the transverse direction of the testing fixture body, and a positioning pin is mounted in the clamp body pin hole; the detection surface of the outer edge of the detection tool body is provided with a spacing timing mark line segment corresponding to the gear timing mark line segment on the camshaft gear. The diesel engine camshaft gear timing mark gauge can realize angle progress detection of a timing mark line segment, the error is controlled within + / -15 ', and the accuracy of a diesel engine timing system can be completely ensured.

Description

Technical Field

[0001] This utility model relates to the field of gear processing technology, and in particular to diesel engine camshaft gear inspection technology. Background Technology

[0002] With the booming development of the freight market, high-horsepower diesel engines are widely used in commercial vehicles due to their advantages such as strong power, high fuel efficiency, and good durability. The overhead camshaft design is commonly used in high-horsepower diesel engines due to its advantages of compact valve train structure, fewer parts, and high transmission efficiency. However, when a valve train malfunction occurs and the camshaft needs to be reinstalled for repair, the initial timing angle between the gears and the camshaft cannot be restored. Incorrect installation can cause cylinder head injury, rendering the entire engine unusable. Typically, 4S service station technicians need to disassemble the engine, remove the gear housing cover, reposition the crankshaft to top dead center of cylinder one, restore the initial timing position of each cylinder, align the timing marks of each gear, and then install the camshaft, gear housing cover, and other accessories. This process is extremely labor-intensive, time-consuming, and costly. Figure 1 and Figure 2 The camshaft gear 4 shown has multiple timing mark segments 8 designed on its end face for easy timing system maintenance. These segments establish a timing angle relationship with the cam on the camshaft through the locating pin hole of the camshaft gear, and mark the position of the top stop of the camshaft for each mark. When the timing mark segment of the camshaft gear is flush with the cylinder head, the timing angle of the corresponding gear train is aligned, which is simple, convenient, and efficient. However, this also requires that the angle of the timing mark segment relative to the pin hole be accurate to ensure the accuracy of the entire diesel engine timing system. Currently, because the timing mark segment is laser-processed, the line depth is relatively shallow, and there is no effective method to detect the angle of the mark, resulting in a large error in adjusting the diesel engine timing system. Utility Model Content

[0003] To address the aforementioned problems with the existing methods for detecting the timing marks of diesel engine camshaft gears, this invention provides a timing mark inspection tool for diesel engine camshaft gears.

[0004] The technical solution adopted by this utility model to achieve the above-mentioned objective is as follows: a timing mark gauge for a diesel engine camshaft gear includes a gauge body 3 and a spindle 1. The spindle 1 is horizontally installed in the center hole of the gauge body 3, and the gauge body 3 and the spindle 1 are fixedly connected. One end of the spindle 1 on the same side as the detection surface of the gauge body 3 is designed to mate with the center hole of the camshaft gear 4. A clamping pin hole 6 is provided on the gauge body 3 horizontally corresponding to the gear pin hole 9 of the camshaft gear 4, and a positioning pin 2 is installed in the clamping pin hole 6. A timing mark segment 7 is provided on the detection surface of the outer edge of the gauge body 3, corresponding to the gear timing mark segment 8 on the camshaft gear 4.

[0005] The end of the spindle 1 opposite to the mounting end of the camshaft gear 4 is a handle 5.

[0006] One end of the positioning pin 2 is clearance-fitted with the gear pin hole 9 of the camshaft gear 4, with a clearance of 0.05-0.08mm. The other end of the positioning pin 2 is interference-fitted with the clamp body pin hole 6, with an interference amount of 0.02-0.05mm.

[0007] The outer edge detection surface of the clamp body 3 is cut with timing mark segments 7 at positions corresponding to 35°, 95°, 155°, 180°, 215°, 275°, and 335°.

[0008] The timing mark gauge for diesel engine camshaft gears of this utility model can detect the angular progress of timing mark line segments, and the error is controlled within ±15′, which can fully guarantee the accuracy of the diesel engine timing system. Attached Figure Description

[0009] Figure 1 This is a top view of the camshaft gear.

[0010] Figure 2 This is a side view sectional view of the camshaft gear.

[0011] Figure 3 This is a top view of the timing mark gauge for the diesel engine camshaft gear of this utility model.

[0012] Figure 4 This is a side sectional view of the timing mark gauge for diesel engine camshaft gears according to this utility model.

[0013] Figure 5 This is a top view of the timing mark gauge for the diesel engine camshaft gear of this utility model.

[0014] Figure 6 This is a side sectional view of the timing mark gauge for diesel engine camshaft gears according to this utility model.

[0015] In the diagram: 1. Mandrel, 2. Locating pin, 3. Inspection body, 4. Camshaft gear, 5. Handle, 6. Clamp body pin hole, 7. Spacing timing mark line segment, 8. Gear timing mark line segment, 9. Gear pin hole. Detailed Implementation

[0016] The timing mark gauge for the diesel engine camshaft gear of this utility model is as follows: Figure 3 and Figure 4As shown, a mandrel 1 is mounted on the fixture 3 and connected to it by welding. The left end of the mandrel 1 is clearance-fitted with the inner hole of the camshaft gear 4 to center the fixture. The other end of the mandrel 1 is designed with a handle 5 for easy handling and use by the inspector. The mandrel 1 is welded to the fixture 3. A fixture pin hole 6 is set on the fixture 3 according to the center position of the camshaft gear pin hole 9. A positioning pin 2 is installed at the fixture pin hole 6. The diameter of the left end of the positioning pin 2 is clearance-fitted with the gear pin hole 9. The clearance is controlled at 0.05-0.08mm to facilitate the insertion of the positioning pin. The right end of the positioning pin 2 is interference-fitted with the fixture pin hole 6. The interference amount is 0.02-0.05mm to firmly fix the positioning pin on the fixture. The fixture is wire-cut with a timing mark segment 7 at positions corresponding to 35°, 95°, 155°, 180°, 215°, 275°, and 335°. The angle error can be guaranteed to be within ±15′. The starting angle 'a' of the timing mark segment can be designed individually according to different gears, and b1 to b6 are marked on the corresponding segment positions, corresponding to the top dead center position of the camshaft of cylinders one to six. TCD and ETCD are the positions for adjusting the ignition advance angle of the corresponding cylinder.

[0017] like Figure 5 and Figure 6 As shown, during the use of the fixture, hold the handle 5 of the mandrel 1 and insert the fixture into the camshaft gear 4 from the left end, ensuring a clearance fit between the left end of the mandrel 1 and the inner hole of the camshaft gear 4. The fixture positioning pin 2 is inserted into the gear pin hole 9 to complete the positioning. The position of the timing mark segment 7 on the fixture should coincide with the position of the timing mark segment 8 on the gear. If they do not coincide, it indicates an angular error greater than 30′, and the timing mark marking equipment should be adjusted immediately. Simultaneously, the markings must be consistent vertically to effectively detect whether workers have made mistakes.

Claims

1. A timing mark gauge for a diesel engine camshaft gear, characterized in that: The device includes a test piece (3) and a spindle (1). The spindle (1) is installed laterally in the center hole of the test piece (3), and the test piece (3) and the spindle (1) are fixedly connected. The end of the spindle (1) on the same side as the test surface of the test piece (3) is a structure that mates with the center hole of the camshaft gear (4). The test piece (3) is provided with a clamping pin hole (6) corresponding to the gear pin hole (9) of the camshaft gear (4) laterally. A positioning pin (2) is installed in the clamping pin hole (6). The test surface of the outer edge of the test piece (3) is provided with a spacing timing mark line segment (7) corresponding to the gear timing mark line segment (8) on the camshaft gear (4).

2. The timing mark fixture for a diesel engine camshaft gear according to claim 1, characterized in that: The end of the spindle (1) opposite to the mounting end of the camshaft gear (4) is a handle (5).

3. The timing mark fixture for a diesel engine camshaft gear according to claim 1, characterized in that: One end of the positioning pin (2) is clearance-fitted with the gear pin hole (9) of the camshaft gear (4) with a clearance of 0.05-0.08 mm. The other end of the positioning pin (2) is interference-fitted with the clamp body pin hole (6) with an interference amount of 0.02-0.05 mm.

4. The timing mark fixture for a diesel engine camshaft gear according to claim 1, characterized in that: The outer edge detection surface of the detection device (3) is cut with timing mark segments (7) at positions corresponding to 35°, 95°, 155°, 180°, 215°, 275°, and 335°.

Images