Vehicle engine camshaft timing assembly tooling and phase adjustment method

Abstract

The present invention relates to the field of engine technology, and more particularly to a vehicle engine camshaft timing assembly tool and a phase adjustment method. The vehicle engine camshaft timing assembly tool includes a camshaft locating pin, the camshaft locating pin including a mounting portion and an insertion portion connected to each other, the mounting portion and the insertion portion not being coaxial, the mounting portion being rotatably connected to an upper cover of the engine, the insertion portion being inserted into a locating hole of the camshaft, the insertion portion abutting against the hole wall of the locating hole, and the camshaft locating pin being configured such that when adjusting the phase angle of the camshaft, the camshaft and the camshaft locating pin are rotated so that the insertion portion always abuts against the hole wall of the locating hole. The present invention can accurately control the rotation angle of the camshaft, thereby achieving the purpose of quickly and accurately adjusting the initial phase angle of the camshaft.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a timing assembly tool for a camshaft of a complete vehicle engine and a phase adjustment method. Background Art

[0002] Variable valve timing technology (VVT) plays a significant role in improving vehicle power, economy and emissions, so this technology is widely used in automotive engines.

[0003] After engine assembly, the relationship between the camshaft angle and the crankshaft angle is fixed, known as the initial camshaft phase angle. The initial phase angle for each engine model is determined during the development process based on the engine's characteristics. Under varying vehicle driving conditions, variable valve timing (VVT) adjusts the camshaft's relative rotation angle based on the initial camshaft phase angle, altering the opening and closing times of the intake and exhaust valves. This, in turn, changes the engine's intake state, ultimately improving various engine performance characteristics.

[0004] During vehicle development, performance, emissions, and calibration tests are conducted. While the engine control parameters of the two vehicles are identical, the actual opening and closing times of the intake and exhaust valves are still inconsistent due to different camshaft initial phase angles. This can lead to discrepancies in the test results, affecting comparisons. To eliminate the impact of this initial camshaft phase angle on test results, the camshaft initial phase angle is adjusted to minimize the difference between the comparison vehicles.

[0005] Current engine camshaft timing assembly generally utilizes a dowel pin system: camshaft dowel pins and dowel pin holes on the camshaft establish the relative position between the crankshaft, crankshaft timing gear, and flywheel. With the crankshaft fixed relative to the camshaft, the initial camshaft phase angle is determined by the dowel pin fixture on the upper cover, the clearance between the camshaft dowel pin and the dowel hole, and the location of the dowel hole on the camshaft.

[0006] The current method for adjusting the camshaft's initial phase angle is to loosen the bolts securing the camshaft to the phase adjuster and rotate the crankshaft pulley to change the relative angle between the crankshaft and camshaft. On the one hand, a torque wrench is required to rotate the engine crankshaft, which is difficult and laborious to operate within the vehicle's engine compartment. When adjusting the camshaft's initial phase within the vehicle's engine using tappets, micrometers, inclinometers, etc., data stability is extremely difficult to ensure due to limited operating space, making it difficult to accurately rotate to the desired angle (the camshaft's initial phase angle that requires adjustment is generally small). On the other hand, to facilitate the installation of the locating pin, the camshaft locating pin and the camshaft's locating hole are designed to be a clearance fit. When the camshaft and phase adjuster are re-tightened, the camshaft's initial phase angle will deviate again.

[0007] Therefore, a vehicle engine camshaft timing assembly tool and phase adjustment method are needed to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to provide a vehicle engine camshaft timing assembly tool and phase adjustment method, which can accurately control the rotation angle of the camshaft and achieve the purpose of quickly and accurately adjusting the initial phase angle of the camshaft.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] A vehicle engine camshaft timing assembly tool includes: a camshaft locating pin, the camshaft locating pin includes a mounting portion and an insertion portion that are connected to each other, the mounting portion and the insertion portion are not on the same axis, the mounting portion is rotatably connected to the upper cover of the engine, the insertion portion is inserted into the locating hole of the camshaft, the insertion portion abuts against the hole wall of the locating hole, and the camshaft locating pin is configured to: when adjusting the phase angle of the camshaft, rotate the camshaft and the camshaft locating pin so that the insertion portion always abuts against the hole wall of the locating hole.

[0011] Furthermore, a screwing portion is fixedly provided at one end of the mounting portion away from the insertion portion, and the screwing portion is coaxially arranged with the mounting portion.

[0012] Furthermore, the screwing portion, the mounting portion and the inserting portion are an integrated structure.

[0013] Furthermore, the cross section of the screwing portion is a regular hexagon.

[0014] Furthermore, a threaded hole is provided on the upper cover, the mounting portion has an external thread matching the threaded hole, and the mounting portion is screwed to the threaded hole via the external thread.

[0015] The phase adjustment method uses the above-mentioned vehicle engine camshaft timing assembly tool to adjust the phase angle of the camshaft, including the following steps:

[0016] S1. Remove the bolt plug from the threaded hole on the upper cover of the engine, rotate the crankshaft pulley clockwise, observe the positioning hole of the camshaft through the threaded hole, and stop rotating the crankshaft pulley when the positioning hole is vertically upward;

[0017] S2. Inserting the insertion portion of the camshaft locating pin into the locating hole, and threading the mounting portion into the threaded hole;

[0018] S3. Insert the crankshaft locating pin into the crankshaft locating hole and fix the flywheel plate so that the teeth of the flywheel plate engage with the teeth of the flywheel plate;

[0019] S4, loosening the phase adjuster used to fix the camshaft;

[0020] S5. According to the phase adjustment requirement, the camshaft positioning pin is rotated and the camshaft is rotated simultaneously, so that the insertion portion is always in contact with the hole wall of the positioning hole;

[0021] S6. After the phase angle of the camshaft is adjusted as required, tighten the phase adjuster.

[0022] Furthermore, in step S5, if phase advancement is required, the camshaft is adjusted to rotate clockwise, and if phase lag is required, the camshaft is adjusted to rotate counterclockwise.

[0023] Furthermore, a relationship table between the camshaft locating pin and the camshaft rotation angle is obtained according to the deviation value between the axis of the insertion portion and the axis of the mounting portion.

[0024] Furthermore, it also includes:

[0025] S7, obtaining the adjusted phase angle of the camshaft;

[0026] S8. If the adjusted phase angle of the camshaft has a deviation, repeat steps S5 to S7 according to the deviation value to perform adjustments.

[0027] Furthermore, in step S7, the adjusted phase angle of the camshaft is obtained through the ECU or by measurement.

[0028] Beneficial effects of the present invention:

[0029] The present invention provides a vehicle engine camshaft timing assembly tool, comprising a camshaft locating pin, the camshaft locating pin comprising an eccentrically arranged mounting portion and an inserting portion, the mounting portion being rotatably mounted on an upper cover of the engine, the inserting portion being inserted into a locating hole of the camshaft, and abutting against the wall of the locating hole, thereby ensuring positioning while eliminating the influence of the gap between the locating hole and the inserting portion on the camshaft phase angle. The initial phase angle of the camshaft is adjusted by simultaneously rotating the camshaft and the camshaft locating pin. When adjusting the initial phase angle of the camshaft, the camshaft locating pin is rotated, and the angle of the camshaft locating pin changes the position of the inserting portion, correspondingly adjusting the camshaft locating angle, thereby adjusting the initial phase of the camshaft, thereby achieving the purpose of adjusting the initial phase angle of the camshaft, thereby resolving the operational difficulties and difficulty in ensuring adjustment accuracy caused by the conventional method of adjusting the initial phase of the camshaft by rotating the crankshaft on the vehicle. Moreover, the vehicle engine camshaft timing assembly tool directly adjusts the phase angle of the camshaft, thereby reducing the system error caused by the interaction between the crankshaft, chain, tensioner, camshaft, and adjustment tool compared to the traditional method. By adopting the above method, the rotation angle of the camshaft can be accurately controlled, thereby achieving the purpose of quickly and accurately adjusting the initial phase angle of the camshaft.

[0030] The present invention provides a phase adjustment method that uses the vehicle engine camshaft timing assembly tooling as described above to adjust the phase angle of the camshaft, which can accurately control the rotation angle of the camshaft and achieve the purpose of quickly and accurately adjusting the initial phase angle of the camshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a camshaft locating pin in a vehicle engine camshaft timing assembly tool of the present invention;

[0032] Figure 2 is a flow chart of a phase adjustment method of the present invention;

[0033] Figure 3 It is a schematic diagram of the camshaft locating pin rotation angle and axis displacement.

[0034] In the picture:

[0035] 1. Camshaft locating pin; 11. Mounting portion; 111. External thread; 12. Insertion portion; 13. Screwing portion. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only show portions relevant to the present invention, not all of them.

[0037] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0038] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0039] When adjusting the initial phase angle of the camshaft, in order to accurately control the rotation angle of the camshaft, the purpose of quickly and accurately adjusting the initial phase angle of the camshaft is achieved. Figure 1 As shown, the present invention provides a vehicle engine camshaft timing assembly tool. The vehicle engine camshaft timing assembly tool includes a camshaft locating pin 1, which includes a mounting portion 11 and an insertion portion 12 connected to each other. The mounting portion 11 and the insertion portion 12 are not coaxial. The mounting portion 11 is rotatably connected to the engine upper cover. The insertion portion 12 is inserted into the camshaft's locating hole and abuts against the hole wall of the locating hole. The camshaft locating pin 1 is configured so that when adjusting the camshaft phase angle, the camshaft and the camshaft locating pin 1 are rotated so that the insertion portion 12 always abuts against the hole wall of the locating hole.

[0040] Because the insertion portion 12 and mounting portion 11 of the camshaft locating pin 1 are designed with an eccentric structure, the eccentric structure causes the position of the insertion portion 12 to differ when the camshaft locating pin 1 is screwed in at different angles, resulting in different camshaft fixing angles and, in other words, different camshaft initial phase angles. Based on this principle, the camshaft initial phase angle can be adjusted by adjusting the screwing angle of the camshaft locating pin 1. During installation of the camshaft locating pin 1 on the engine upper cover, the insertion portion 12 abuts against the wall of the positioning hole, ensuring positioning while eliminating the effect of the gap between the positioning hole and the insertion portion 12 on the camshaft phase angle. This complete vehicle engine camshaft timing assembly tool overcomes the operational difficulties and difficulty in ensuring adjustment accuracy associated with conventional crankshaft-rotating operation for adjusting the camshaft initial phase on a complete vehicle. Furthermore, this complete vehicle engine camshaft timing assembly tool allows for direct adjustment of the camshaft phase angle, reducing system errors caused by the interaction of the crankshaft, chain, tensioner, camshaft, and adjustment tool compared to traditional methods. By adopting the above method, the rotation angle of the camshaft can be accurately controlled, thereby achieving the purpose of quickly and accurately adjusting the initial phase angle of the camshaft.

[0041] Furthermore, a screwing portion 13 is fixedly provided at one end of the mounting portion 11 away from the insertion portion 12, and the screwing portion 13 is coaxially arranged with the mounting portion 11. The screwing portion 13 facilitates the rotation of the mounting portion 11, thereby adjusting the position of the insertion portion 12.

[0042] Furthermore, the screwing portion 13, the mounting portion 11 and the inserting portion 12 are an integrated structure. This configuration facilitates the manufacture of the camshaft locating pin 1 while ensuring the connection strength between the screwing portion 13, the mounting portion 11 and the inserting portion 12.

[0043] Furthermore, the cross section of the screwing portion 13 is a regular hexagon. By designing the screwing portion 13 as a regular hexagonal prism, it is possible to ensure that the screwing portion 13 has sufficient strength and is easy to screw with a wrench, thereby facilitating adjustment of the position of the insertion portion 12.

[0044] Furthermore, the upper cover has a threaded hole, and the mounting portion 11 has an external thread 111 that mates with the threaded hole. The mounting portion 11 is screwed to the threaded hole via the external thread 111. The mounting portion 11 is threadedly fixed to the upper cover, allowing it to rotate while remaining stable after the position of the insert portion 12 is adjusted, thereby ensuring that the position of the insert portion 12 remains unchanged after adjustment. The insert portion 12 mates with a positioning hole on the camshaft to position the camshaft.

[0045] like Figure 2 As shown, this embodiment also provides a phase adjustment method, which uses the above vehicle engine camshaft timing assembly tool to adjust the phase angle of the camshaft, including the following steps:

[0046] S1. Remove the bolt plugs from the threaded holes on the engine's upper cover, rotate the crankshaft pulley clockwise, and observe the camshaft's positioning hole through the threaded hole. Stop rotating the crankshaft pulley when the positioning hole is pointing vertically upward.

[0047] S2. Insert the insertion portion 12 of the camshaft locating pin 1 into the locating hole, and thread the mounting portion 11 into the threaded hole;

[0048] S3. Insert the crankshaft locating pin into the crankshaft locating hole and fix the flywheel plate so that the teeth of the flywheel plate engage with the teeth of the flywheel plate;

[0049] S4. Loosen the phase adjuster used to fix the camshaft;

[0050] S5. According to the phase adjustment requirements, rotate the camshaft positioning pin 1 and the camshaft simultaneously, so that the insertion portion 12 always abuts against the wall of the positioning hole;

[0051] S6. After the camshaft phase angle is adjusted as required, tighten the phase adjuster.

[0052] Furthermore, in step S5, if the phase is to be advanced, the camshaft is adjusted to rotate clockwise, and if the phase is to be delayed, the camshaft is adjusted to rotate counterclockwise. By rotating the camshaft positioning pin 1 according to different needs and correspondingly rotating the camshaft, the phase angle of the camshaft can be quickly adjusted.

[0053] Furthermore, a relationship table between the camshaft positioning pin 1 and the camshaft rotation angle is obtained based on the deviation between the axis of the insertion portion 12 and the axis of the mounting portion 11. Specifically, Figure 3 As shown, when the structure of the camshaft locating pin 1 is determined, the relationship between the rotation angle of the mounting portion 11 and the displacement of the axis of the inserting portion 12 is fixed. Figure 3 In the figure, the large circle is a top view of the mounting portion 11, and the small circle is a top view of the insertion portion 12. The left side of the figure is the original position, and the right side is after the rotation angle α. The calculation formula of the axial displacement l is:

[0054] l=x×sinα

[0055] Where x is the eccentric distance.

[0056] Because the adjustment angle is often very small, the axial displacement is approximately equal to the arc length. According to the arc length calculation formula, the camshaft rotation angle β is approximately calculated as follows:

[0057]

[0058] Where r is the camshaft radius. This relationship allows for a precise relationship table between the camshaft locating pin 1 and the camshaft rotation angle. The data in this relationship table allows for rapid adjustment of the camshaft's initial phase angle. The angle where the axis of the camshaft locating pin 1's insertion portion 12 and mounting portion 11 are parallel to the camshaft axis is defined as 0°. The camshaft locating pin 1's rotation angles α1, α2, α3, and so on are calculated (several points can be reasonably distributed). The corresponding camshaft rotation angles β1, β2, β3, and so on are simultaneously measured to obtain a corresponding relationship table, as shown in Table 1. This relationship table allows for precise adjustment of the camshaft's initial phase angle.

[0059] Relationship table between camshaft positioning pin rotation angle and camshaft rotation angle

[0060]

[0061]

[0062] Furthermore, it also includes:

[0063] S7, obtaining the adjusted phase angle of the camshaft;

[0064] S8. If the adjusted camshaft phase angle has deviations, repeat steps S5 to S7 according to the deviation value to adjust. By checking, it can be determined whether the adjusted camshaft phase angle meets the requirements. If not, continue to adjust until it meets the requirements.

[0065] Furthermore, in step S7, the phase angle of the adjusted camshaft is obtained by reading the ECU or measuring the phase angle of the camshaft. In this way, the phase angle of the adjusted camshaft can be determined, and whether the adjustment is in place can be determined according to the adjustment requirements.

[0066] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. The vehicle engine camshaft timing assembly tool is characterized by: include: A camshaft locating pin (1), comprising a mounting portion (11) and an inserting portion (12) connected to each other, wherein the mounting portion (11) and the inserting portion (12) are not located on the same axis, the mounting portion (11) is rotatably connected to an upper cover of an engine, the inserting portion (12) is inserted into a locating hole of a camshaft, and the inserting portion (12) abuts against a hole wall of the locating hole. The camshaft locating pin (1) is configured such that when adjusting the phase angle of the camshaft, the camshaft and the camshaft locating pin (1) are rotated so that the inserting portion (12) always abuts against the hole wall of the locating hole.

2. The vehicle engine camshaft timing assembly tool according to claim 1, characterized in that: A screwing portion (13) is fixedly provided at one end of the mounting portion (11) away from the insertion portion (12), and the screwing portion (13) is coaxially arranged with the mounting portion (11).

3. The vehicle engine camshaft timing assembly tool according to claim 2, characterized in that: The screwing portion (13), the mounting portion (11) and the inserting portion (12) are an integrated structure.

4. The vehicle engine camshaft timing assembly tool according to claim 2, characterized in that: The cross section of the screwing portion (13) is a regular hexagon.

5. The vehicle engine camshaft timing assembly tool according to claim 1, characterized in that: A threaded hole is provided on the upper cover, and the mounting portion (11) has an external thread (111) that matches the threaded hole. The mounting portion (11) is screwed to the threaded hole via the external thread (111).

6. A phase adjustment method, characterized in that: The phase angle of the camshaft is adjusted by using the vehicle engine camshaft timing assembly tool as described in any one of claims 1 to 5, comprising the following steps: S1. Remove the bolt plug from the threaded hole on the upper cover of the engine, rotate the crankshaft pulley clockwise, observe the positioning hole of the camshaft through the threaded hole, and stop rotating the crankshaft pulley when the positioning hole is vertically upward; S2, inserting the insertion portion (12) of the camshaft positioning pin (1) into the positioning hole, and threading the mounting portion (11) into the threaded hole; S3. Insert the crankshaft locating pin into the crankshaft locating hole and fix the flywheel plate so that the teeth of the flywheel plate engage with the teeth of the flywheel plate; S4, loosening the phase adjuster used to fix the camshaft; S5. According to the phase adjustment requirement, the camshaft positioning pin (1) is rotated and the camshaft is rotated simultaneously, so that the insertion portion (12) always abuts against the hole wall of the positioning hole; S6. After the phase angle of the camshaft is adjusted as required, tighten the phase adjuster.

7. The phase adjustment method according to claim 6, characterized in that: In step S5 , if phase advancement is required, the camshaft is adjusted to rotate clockwise, and if phase lag is required, the camshaft is adjusted to rotate counterclockwise.

8. The phase adjustment method according to claim 6, characterized in that: A relationship table between the camshaft locating pin (1) and the camshaft rotation angle is obtained based on the deviation value between the axis of the insertion portion (12) and the axis of the mounting portion (11).

9. The phase adjustment method according to claim 6, characterized in that: Also includes: S7, obtaining the adjusted phase angle of the camshaft; S8. If the adjusted phase angle of the camshaft has a deviation, repeat steps S5 to S7 according to the deviation value to perform adjustments.

10. The phase adjustment method according to claim 9, characterized in that: In step S7, the adjusted phase angle of the camshaft is obtained through the ECU or by measurement.

Images