Mechanical timing device for a v-type engine and detection method
By designing a mechanical timing device for V-type engines and innovating testing methods, the problems of high testing difficulty and large error in V-type engines have been solved, achieving efficient and accurate testing and assembly, applicable to V8 and inline engines.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA FAW CO LTD
- Filing Date
- 2023-05-26
- Publication Date
- 2026-05-15
AI Technical Summary
Mechanical timing testing of V-type engines is difficult, especially V8 engines. The measurement error is large, and it is difficult to make the testing tools perpendicular, which leads to inaccurate testing or jamming. This increases the testing cost and assembly difficulty, and affects the engine utilization rate and testing efficiency.
A mechanical timing device for a V-type engine was designed, including a verticality adjustment fixture and an innovative testing method. Through specialized testing tools and procedures, the verticality of the dial indicator and the accuracy of the test are ensured. The measurement items are broken down into the engine block and cover parts. The combination of the verticality adjustment fixture and the dial indicator enables multiple recording and calculation of the cam phase deviation.
It improves the accuracy and efficiency of mechanical timing testing for V-type engines, reduces testing costs, increases engine utilization and assembly efficiency, and is applicable to the measurement of inline engines.
Smart Images
Figure CN116717338B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of engine timing technology, specifically a mechanical timing device and testing method for a V-type engine. Background Technology
[0002] V-block engines are generally used in luxury, high-displacement cars. Engines are typically assembled manually, and ensuring accurate mechanical timing through assembly processes is extremely difficult. Accurate mechanical timing is usually ensured through subsequent measurements. For V-type engines, especially large engines like the V8, the large tilt angle makes measurement difficult and prone to error. When finding top dead center, it's difficult to ensure the dial indicator probe is perpendicular to the camshaft when entering through the valve cover hole and contacting the camshaft. Furthermore, it's challenging to resolve occasional jamming issues. For V-type engines, especially large engines like the V8, the cost of the engine assembly and related tests is very high. Accurate measurement and evaluation of mechanical timing, screening for qualified engine assemblies, and using reasonable measurement results to guide the selection of relevant test models allow even poorly assembled engines to be used in other tests. This increases engine utilization, reduces the risk of test failures, and ultimately improves assembly efficiency and mechanical timing accuracy.
[0003] The current method for testing the timing of V-type engines is to insert the timing pins of the crankshaft and camshaft. This method is an inline cylinder block testing method, which has low testing efficiency and it is difficult to ensure that the timing pins are perpendicular to the dial indicator. During the testing process, the pins often get stuck, resulting in inaccurate timing measurements, or repeated testing due to jamming, or even failure to test. However, the perpendicularity between the timing pins and the dial indicator can be ensured by manufacturing special inspection tools. Summary of the Invention
[0004] Engine timing is crucial for engine performance. The tolerance for ordinary engines is within 3 degrees, while that for calibrated engines is within 1 degree, so the accuracy of the test must be guaranteed.
[0005] To address the above problems, this invention provides a V-type engine mechanical timing device and testing method. By manufacturing specialized testing tools and innovative testing methods, this invention analyzes the difficulties encountered in testing engine mechanical timing, evaluates and verifies each sub-element after analysis, thereby determining whether there are key factors affecting engine mechanical timing, and further determining whether a non-conforming engine has the potential to be applied in different test items, ultimately achieving more accurate and efficient guidance for assembly adjustments.
[0006] The technical solution of the present invention is as follows: a V-type engine mechanical timing device, comprising: a verticality adjustment fixture, the verticality adjustment fixture being composed of a locking frame, a pressure spring, a fixing block, a spring fixing seat, and a measuring pin, the measuring pin being sleeved on the spring fixing seat, the spring fixing seat being sleeved on the pressure spring, one end of the pressure spring being fixed on the spring fixing seat, the other end being fixed on the locking frame, the spring fixing seat passing through the locking frame and being slidably connected to the locking frame, and the locking frame being rotatably connected to the fixing block.
[0007] A method for detecting the mechanical timing of a V-type engine includes the following steps:
[0008] S1 determines the initial position of the engine block crankshaft;
[0009] S2 Install verticality adjustment fixture and dial indicator;
[0010] S3 determines the initial position of the engine camshaft timing;
[0011] S4 rotates the crankshaft to observe the changes in the index, records the lift and angle, and evaluates them.
[0012] Further, step S1 specifically involves placing the crankshaft rotation wrench in the corresponding position on the engine, rotating it and inserting the crankshaft locking pin to lock the crankshaft, then fixing the flywheel clamp plate with the flywheel clamp plate bolt to lock the flywheel, and turning on the engine to zero the angle gauge. The zero degree at this time is the initial position of the crankshaft.
[0013] Further, step S2 specifically involves locking the fixing block on the verticality adjusting fixture onto the engine using the verticality adjusting fixture fastening bolts, so that the measuring pin can be inserted into the timing pin hole to be measured, pressing the dial indicator onto the measuring pin, and then turning on the dial indicator to zero.
[0014] Furthermore, the dial indicator is fixed by a bracket, which is telescopic and foldable. The bracket is fixed to a bracket mounting base, which is then fixed to the engine valve cover by base mounting bolts.
[0015] Further, step S3 specifically involves rotating the crankshaft rotation wrench while simultaneously screwing the camshaft timing lock pin into the timing pin hole of the valve cover until it locks in place. This is the initial position of the camshaft timing.
[0016] Further, step S4 specifically involves removing the flywheel retainer, camshaft timing lock pin, and crankshaft lock pin, and then rotating the crankshaft rotary wrench to observe the change in the dial indicator lift.
[0017] Furthermore, S401, based on the theoretical crankshaft angle on the engine's mechanical phase measuring gauge, rotates the crankshaft rotary wrench, observes the angle on the dial gauge, rotates the angle to the theoretical crankshaft angle, and records the corresponding dial gauge value;
[0018] S402 adds 5 degrees to the crankshaft angle, rotates the crankshaft rotary wrench until the theoretical crankshaft angle is reached, and records the corresponding dial indicator value;
[0019] S403 adds 5 degrees to the crankshaft angle, rotates the crankshaft rotary wrench until the theoretical crankshaft angle is reached, and records the corresponding dial indicator value;
[0020] S404 Continue to rotate the crankshaft rotary wrench. After passing the maximum lift value, reach the lowering stage and observe the change in the lift value during the lowering stage. When the lift value of the dial indicator in the lowering stage is consistent with the lift value recorded in the rising stage in step S403, record the crankshaft angle at this time.
[0021] S405 Rotate the crankshaft rotary wrench. When the dial indicator's lift value in the descending segment matches the dial indicator's lift value in the ascending segment in step S402, record the crankshaft angle at this time.
[0022] S406 Rotate the crankshaft with a rotary wrench. When the dial indicator's lift value in the descending segment matches the dial indicator's lift value in the ascending segment in step S401, record the crankshaft angle at this point.
[0023] Further, in step S4, the evaluation is as follows: the measured value of the cam phase for each group is obtained according to the cam phase measurement calculation formula. The average value of the cam phase measurement after averaging the three groups of measured cam phase values is obtained. The cam phase deviation is compared with the theoretical value of the cam phase. If the tolerance is within 3 degrees, it is qualified; if the tolerance is not met, the cam phase angle is adjusted, and S401-S406 are continued.
[0024] The beneficial effects of this invention are as follows:
[0025] This invention analyzes the difficulties encountered in testing engine mechanical timing by manufacturing specialized testing tools and innovative testing methods. It evaluates and verifies each sub-element after analysis to determine whether it is a key factor affecting engine mechanical timing. This allows for the assessment of whether a non-compliant engine has the potential for application in different testing items, ultimately providing more accurate and efficient guidance for assembly adjustments. This invention is also applicable to the measurement of mechanical timing in inline engines, with a relatively simple measurement process. The mechanical timing of a V8 engine is broken down into the following measurement items: engine block and engine cover. Adjusting the verticality adjustment fixture ensures the dial indicator is perpendicular to the measuring pin. The average of the three measured cam phase values (open and closed sections) is compared with the theoretical cam phase value to obtain the final cam phase deviation. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the installation of the V8 cylinder block mechanical timing measurement cylinder block position according to the present invention.
[0027] Figure 2 This is a schematic diagram of the crankshaft lock pin body of the present invention.
[0028] Figure 3 This is a schematic diagram showing the installation position of the mechanical timing measurement cover for the V8 cylinder block of the present invention.
[0029] Figure 4 This is a flowchart of the measurement process of the present invention.
[0030] Figure 5 This is a schematic diagram (I) of the verticality adjustment fixture of the present invention.
[0031] Figure 6 This is a schematic diagram (II) of the verticality adjustment fixture of the present invention.
[0032] Figure 7 This is a schematic diagram of the crankshaft rotary wrench of the present invention.
[0033] Figure 8 This is a schematic diagram of the camshaft timing lock pin of the present invention.
[0034] In the picture:
[0035] 1-Crankshaft lock pin; 2-Flywheel clamp bolt; 3-Flywheel clamp; 4-Angle gauge; 6-Camshaft timing lock pin; 7-Verticality adjustment fixture; 8-Dial gauge; 9-Gilt gauge holder; 10-Gilt gauge holder fixing base; 11-Base fixing bolt; 12-Verticality adjustment fixture fastening bolt; 14-Locking bracket; 15-Pressure spring; 16-Fixing block; 17-Spring fixing seat; 18-Measuring pin; 19-Crankshaft rotary wrench. Detailed Implementation
[0036] It should be noted that in the description of this invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation.
[0037] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; a connection can be a mechanical connection or an electrical connection; a link can be a direct connection or an indirect connection through an intermediate medium, and can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0038] Overview of the testing and evaluation methods for V-type engine mechanical timing:
[0039] Measurement object: V8 engine mechanical timing
[0040] Measuring equipment: universal angle gauge, dial indicator, special inspection tools, etc.
[0041] Specialized measuring fixtures: This invention requires specialized measuring tools, such as... Figure 5 Figure 6 As shown, the verticality adjustment fixture 7 consists of a locking frame 14, a pressure spring 15, a fixing block 16, a spring fixing seat 17, and a measuring pin 18. The connection relationship is as follows: the spring fixing seat 17 is placed on the locking frame 14, the pressure spring 15 is placed on the spring fixing seat 17, and the measuring pin 18 is fixed on the spring fixing seat 17.
[0042] Breakdown of measurement items:
[0043] The mechanical timing of a V8 engine is broken down into the following measurement items, such as Figure 1 , Figure 3 As shown:
[0044] Engine block section: Insert crankshaft locking pin 1 into the cylinder block to lock the crankshaft, then fix the flywheel with flywheel locking plate 3 and flywheel locking plate bolt 2, and at the same time turn on the engine and reset the angle gauge 4 to zero: This method is to determine whether the crankshaft is in the initial position;
[0045] Engine cover section: The camshaft timing lock pin 6 is placed inside the valve cover. The verticality adjustment fixture 7 is fixed above the valve cover by the verticality adjustment fixture fastening bolt 12. Then, the gauge holder mounting base 10 is placed on the valve cover by the base fixing bolt 11. The dial indicator 8 is then placed inside the verticality adjustment fixture 7. The dial indicator 8 is attached to the gauge holder mounting base 10 by the gauge holder 9. The dial indicator 8 is zeroed and ready for use. This item ensures that the camshaft is in the correct theoretical position, i.e., the initial position, and also ensures that the dial indicator 8 is vertically installed. If there is any jamming, the verticality adjustment fixture 7 can be adjusted to make the two perpendicular. Under normal circumstances, it is perpendicular when installed.
[0046] Measurement Procedure Instructions
[0047] Measurement flowchart as follows Figure 1 , 3 As shown in Figure 7, it consists of 8 steps:
[0048] S1 - Initial crankshaft position determined;
[0049] S2 - Install dial gauge;
[0050] S3 - Install verticality adjustment fixture;
[0051] S4 - Install camshaft timing lock pin;
[0052] S5 - Rotate the crankshaft to observe the changes in the index;
[0053] S6 - Record lift;
[0054] S7 - Records corners;
[0055] S8 - Calculation and Evaluation.
[0056] The measurement steps are as follows:
[0057] The first step is to determine the initial position of the crankshaft.
[0058] like Figure 1 As shown, rotate the crankshaft rotation wrench 19 and insert the crankshaft locking pin 1 to lock it. Then fix the flywheel clamp 3 with the flywheel clamp bolt 2 to lock the flywheel, thus determining the initial position of the crankshaft. At this time, turn on the angle gauge 4 and reset it to zero. The zero degree at this time is the initial position of the crankshaft.
[0059] The second step is to install the dial indicator.
[0060] like Figure 3 , 5 As shown in Figure 6, the fixing block 16 is fixed to the valve cover by the verticality adjustment tool fastening bolt 12. Then, the spring fixing seat 17 is installed on the locking bracket 14. Then, the pressure spring 15 is installed on the spring fixing seat 17. Then, the measuring pin 18 is installed at the lower end of the spring fixing seat 17. Then, the measuring pin 18 is placed into the timing pin hole to be measured, and the dial indicator 8 is pressed on the measuring pin 18. The dial indicator 8 is kept vertical by the instrument holder 9 and does not get stuck during the up and down movement. Finally, the instrument holder 9 is attached to the instrument holder fixing base 10 and the machine is turned on and zeroed for use.
[0061] The third step is to install the verticality adjustment fixture.
[0062] like Figure 5 , 6 As shown, ensuring the verticality of the dial indicator is crucial during V8 engine mechanical timing measurement, and installation is difficult. To address this, the verticality adjustment fixture 7 is installed as follows: First, the spring retainer 17 is installed on the locking bracket 14; then, the pressure spring 15 is installed on the spring retainer 17; next, the measuring pin 18 is installed at the lower end of the spring retainer 17; finally, the locking bracket 14 is installed on the fixing block 16 for later use.
[0063] Fourth step, install the camshaft timing lock pin.
[0064] like Figure 3 , 7 As shown, rotating the crankshaft wrench 19 will screw the camshaft timing lock pin 6 into the timing pin hole of the valve cover until it locks in place. This is the initial position of the camshaft timing.
[0065] Step 5: Rotate the crankshaft and observe the index change
[0066] As Figure 1 shown in Fig. 3 / 7, first remove the flywheel clamping plate bolt 2 to remove the flywheel clamping plate 3, then remove the camshaft timing locking pin 6 on the valve cover, then remove the crankshaft locking pin 1, and finally rotate the crankshaft rotation wrench 19 to observe the change in the lift of the dial indicator 8. According to the theoretical crankshaft angle on the engine-mounted mechanical phase measuring instrument, one person rotates the crankshaft rotation wrench 19 while another person tells the angle of the angle meter 4. Through the cooperation of the two people, the angle is rotated until the theoretical crankshaft angle is reached. At this time, record the corresponding value on the dial indicator 8; then continue to rotate the crankshaft rotation wrench 19 with the crankshaft angle increased by 5 degrees until the theoretical crankshaft angle is reached. At this time, record the corresponding value on the dial indicator 8 for the second time; then continue to rotate the crankshaft rotation wrench 19 with the crankshaft angle increased by 5 degrees until the theoretical crankshaft angle is reached. At this time, record the corresponding value on the dial indicator 8 for the third time; when three sets of rising section dial indicator values are recorded according to the theoretical crankshaft angle, continue to rotate the crankshaft to pass through the maximum lift position of the cam. At this time, it is necessary to determine the corresponding crankshaft angle of the falling section according to the three sets of rising section lift values just recorded; one person rotates the wrench to rotate the crankshaft and tells the change in the lift value of the falling section. When the lift value of the dial indicator in the falling section is the same as the lift value recorded in the rising section, record the crankshaft angle at this time. After recording, tell the rising section lift of the second set of cams. Continue to rotate the crankshaft. When the lift value of the dial indicator in the falling section is the same as the lift value recorded in the rising section, record the crankshaft angle at this time until the last set is completed; finally, we calculate the actual measured value of the cam phase for each group according to the cam phase measurement calculation formula. After averaging the three sets of measured cam phase values, compare the average value of the cam phase measurement with the theoretical value of the cam phase to obtain the final cam phase deviation. If it meets the tolerance requirements, it is qualified; otherwise, the cam phase angle needs to be adjusted.
[0067] There are multiple camshafts on a V-type engine, and there are multiple cams on each camshaft. The method of the present invention can only test one cam at a specific position on one camshaft each time, and it needs to be tested multiple times to complete the testing of all camshafts.
[0068] The specific adjustment of the cam phase angle is as follows: Lock the qualified camshaft, loosen the unqualified camshaft, rotate the wrench through the angle meter, and according to the value exceeding the tolerance, rotate the corresponding deviation angle to the theoretical position. Then lock the unqualified camshaft, loosen the qualified camshaft end, and measure again.
[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be included within the scope of protection of the present invention. Furthermore, all content not described in detail in this specification is prior art known to those skilled in the art.
[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
Claims
1. A mechanical timing device for a V-type engine, characterized in that, include: A verticality adjustment fixture is provided, comprising a locking frame, a pressure spring, a fixing block, a spring fixing seat, and a measuring pin. The measuring pin is sleeved on the spring fixing seat, and the spring fixing seat is sleeved on the pressure spring. One end of the pressure spring is fixed on the spring fixing seat, and the other end is fixed on the locking frame. The spring fixing seat passes through the locking frame and is slidably connected to the locking frame. The locking frame is rotatably connected to the fixing block.
2. A method for detecting the mechanical timing of a V-type engine, characterized in that, Includes the following steps: S1 determines the initial position of the engine block crankshaft; S2 installs the device and dial gauge as described in claim 1; S3 determines the initial position of the engine camshaft timing; S4 rotates the crankshaft to observe the changes in the index, records the lift and angle, and evaluates them.
3. The method for detecting the mechanical timing of a V-type engine as described in claim 2, characterized in that, Step S1 is as follows: place the crankshaft rotation wrench in the corresponding position on the engine, rotate it and insert the crankshaft locking pin to lock the crankshaft, then fix the flywheel clamp plate with the flywheel clamp plate bolt to lock the flywheel, turn on the engine and reset the angle gauge to zero. The zero degree at this time is the initial position of the crankshaft.
4. The method for detecting the mechanical timing of a V-type engine as described in claim 3, characterized in that, Step S2 specifically involves locking the fixing block on the verticality adjusting fixture onto the engine using the verticality adjusting fixture fastening bolts, allowing the measuring pin to be inserted into the timing pin hole to be measured, pressing the dial indicator onto the measuring pin, and then turning on the dial indicator to zero.
5. The method for detecting the mechanical timing of a V-type engine as described in claim 4, characterized in that, The dial indicator is fixed by a bracket, which is telescopic and foldable. The bracket is fixed on a bracket mounting base, which is fixed to the engine valve cover by base mounting bolts.
6. The method for detecting the mechanical timing of a V-type engine as described in claim 4, characterized in that, Step S3 specifically involves rotating the crankshaft rotary wrench while simultaneously screwing the camshaft timing lock pin into the timing pin hole of the valve cover until it locks in place. This is the initial position of the camshaft timing.
7. The method for detecting the mechanical timing of a V-type engine as described in claim 6, characterized in that, Step S4 specifically involves removing the flywheel retainer, camshaft timing lock pin, and crankshaft lock pin, and then rotating the crankshaft rotary wrench to observe the change in the dial indicator lift.
8. The method for detecting the mechanical timing of a V-type engine as described in claim 7, characterized in that, The method of observing the change in dial indicator lift by rotating the crankshaft and wrench includes the following steps: S401 uses the theoretical crankshaft angle on the engine's mechanical phase gauge to rotate the crankshaft rotary wrench, observes the angle gauge, rotates the angle to the theoretical crankshaft angle, and records the corresponding dial gauge value. S402 adds 5 degrees to the crankshaft angle, rotates the crankshaft rotary wrench until the theoretical crankshaft angle is reached, and records the corresponding dial indicator value; S403 adds 5 degrees to the crankshaft angle, then rotates the crankshaft rotary wrench until the theoretical crankshaft angle is reached, and records the corresponding dial indicator value. S404 Continue to rotate the crankshaft rotary wrench. After passing the maximum lift value, reach the lowering stage and observe the change in the lift value during the lowering stage. When the lift value of the dial indicator in the lowering stage is consistent with the lift value recorded in the rising stage in step S403, record the crankshaft angle at this time. S405 Rotate the crankshaft rotary wrench. When the dial indicator's lift value in the descending segment matches the dial indicator's lift value in the ascending segment in step S402, record the crankshaft angle at this time. S406 Rotate the crankshaft with a rotary wrench. When the dial indicator's lift value in the descending segment matches the dial indicator's lift value in the ascending segment in step S401, record the crankshaft angle at this point.
9. The method for detecting the mechanical timing of a V-type engine as described in claim 8, characterized in that, In step S4, the evaluation is as follows: the measured value of the cam phase for each group is obtained according to the cam phase measurement calculation formula. The average value of the measured values of the three groups of cam phases is taken and compared with the theoretical value of the cam phase to obtain the cam phase deviation. If the tolerance is within 3 degrees, it is qualified; if the tolerance is not met, the cam phase angle is adjusted and steps S401-S406 are continued.