Crankshaft static balance measuring instrument
By designing a crankshaft static balance instrument for multi-directional static balance measurement, the problem of incomplete measurement in the prior art is solved, and efficient and accurate crankshaft static balance detection is achieved. It is suitable for crankshaft connecting rod components of different sizes, improving detection efficiency and safety.
Patent Information
- Application Number
- CN202422575461.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-10-24
AI Technical Summary
The existing crankshaft static balance instruments can only complete static balance measurements in a single direction, lack comprehensive assessments of the two directions of the crankshaft, low measurement accuracy and poor interchangeability of the tooling design, which cannot meet the measurement needs of crankshafts of different sizes.
A crankshaft static balance measuring instrument including a base, front bracket and rear bracket is designed, equipped with positioning blocks, measuring rods and weights, which can perform static balance measurements in two directions (vertical and horizontal), and achieve multi-dimensional adaptability through semicircular keyways and slidable weights, improving measurement accuracy and efficiency.
It realizes static balance measurement of the crankshaft in two directions, improves measurement accuracy and efficiency, is suitable for crankshaft connecting rod components of different sizes, simplifies tooling design, and improves product qualification rate and safety.
Smart Images
Figure CN223295576U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a detection instrument, in particular to a crankshaft static balance measuring instrument. Background Art
[0002] The crankshaft is a critical component in internal combustion engines and other mechanical equipment, bearing the engine's explosive force and inertial forces. During high-speed operation, crankshaft imbalance can cause vibration, noise, and wear and damage to other components. Therefore, to ensure crankshaft stability and reliability during operation, it is crucial to perform a crankshaft static balance test.
[0003] The crankshaft-connecting rod assembly of a piston engine requires a non-homogeneous circumferential structure because it must balance reciprocating and rotational inertia forces. Design calculations can determine the balancing torque, and thus the crankshaft assembly's design structure. However, due to mold and machining accuracy, product dimensions will inevitably deviate from the nominal design values. Severe static imbalance in the crankshaft can lead to excessive engine vibration, noise, high failure rates, and even serious safety accidents. Therefore, crankshaft static balance measurement is an essential step in product inspection.
[0004] Existing crankshaft static balancing instruments can usually only complete static balance measurements in a single direction, lack the ability to assess the static balance of the crankshaft in two directions, and the measurement is not comprehensive enough, the data accuracy is low, and the interchangeability of the tooling design is low. Summary of the Invention
[0005] Purpose of the utility model: The purpose of the utility model is to provide a crankshaft static balance measuring instrument which has high measurement efficiency, can simultaneously measure two positions of the crankshaft, and is suitable for crankshaft-connecting rod assemblies of different sizes.
[0006] Technical solution: The crankshaft static balance measuring instrument described in the utility model includes a base, on which a front bracket and a rear bracket are provided. The front crankshaft and the rear crankshaft of the crankshaft assembly to be measured are placed on the front bracket and the rear bracket respectively. A positioning block is installed on the front crankshaft, and a left measuring rod and a right measuring rod are installed on the left and right sides of the positioning block respectively. A weight is provided on the left measuring rod or the right measuring rod.
[0007] Preferably, a first keyway and a second keyway for installing a semicircular key are respectively provided on the upper side and the left side of the positioning block.
[0008] Preferably, the weights are freely slidable on the left measuring rod and the right measuring rod.
[0009] Preferably, the inner hole of the positioning block is a tapered hole, which is assembled on the front end conical surface of the front crankshaft.
[0010] Preferably, the left measuring rod and the right measuring rod are both millimeter scales.
[0011] Preferably, the left measuring rod and the right measuring rod are threadedly connected to the positioning block through threaded holes on the left and right sides of the positioning block respectively.
[0012] Preferably, the upper ends of the front bracket and the rear bracket are designed as knife edges.
[0013] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The measuring method is simple, and the data on whether the crankshaft static balance is qualified can be obtained through the measuring method in a very short time, which greatly improves the inspection efficiency and qualified rate of the product; (2) By setting two semicircular key slots, the static balance measurement of the crankshaft connecting rod assembly can be realized at two positions where the line connecting the center of mass and the geometric center is located in the vertical and horizontal directions; (3) The measuring instrument is simple to make and the parts are easy to assemble and disassemble; (4) The measuring instrument can be widely used for the static balance measurement of crankshaft connecting rod assemblies of different sizes, and it is only necessary to change the size of the tapered hole in the measuring positioning block and the installation size of the semicircular key; (5) By replacing weights of different weights, the static balance of crankshafts of different weights can be measured. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 This is a schematic diagram of the overall appearance of the utility model;
[0015] Figure 2 Main view for static balance measurement in vertical direction;
[0016] Figure 3 This is the side view of static balance measurement in the vertical direction;
[0017] Figure 4 It is a stereogram for static balance measurement in the vertical direction;
[0018] Figure 5 Main view for static balance measurement in horizontal direction;
[0019] Figure 6 This is the side view of static balance measurement in the horizontal direction;
[0020] Figure 7 This is a stereogram for static balance measurement in the horizontal direction. DETAILED DESCRIPTION
[0021] The technical solution of the present utility model will be further described below in conjunction with the embodiments.
[0022] As shown in the accompanying drawings, the crankshaft static balancing measuring instrument described in the present invention includes a base 1, a front bracket 2 and a rear bracket 3 are provided on the base 1, and a front crankshaft 4 and a rear crankshaft 5 for placing the components to be measured are respectively provided on the front bracket 2 and the rear bracket 3. A positioning block 6 is installed on the front crankshaft 4, and a left measuring rod 7 and a right measuring rod 8 are respectively installed on the left and right sides of the positioning block 6. A first keyway 9 and a second keyway 10 for installing a semicircular key are respectively provided on the upper side and the left side of the positioning block 6, and also includes a weight 11 on the left measuring rod 7 or the right measuring rod 8.
[0023] The weight 11 is freely slidable on the left measuring rod 7 and the right measuring rod 8 .
[0024] The inner hole of the positioning block 6 is a tapered hole, which is assembled on the front end tapered surface of the front crankshaft 4.
[0025] The left measuring rod 7 and the right measuring rod 8 are both millimeter scales for determining the measuring position of the weight 11 .
[0026] The left measuring rod 7 and the right measuring rod 8 are respectively threadedly connected to the positioning block 6 through the threaded holes on the left and right sides of the positioning block 6.
[0027] The upper ends of the two brackets are designed with knife edges to reduce the friction resistance between the crankshaft and the bracket support surface during the measurement process, thereby improving the measurement accuracy of the static balance value.
[0028] The working principle of the crankshaft static balance measuring instrument described in the utility model is as follows:
[0029] like Figure 2-Figure 4 This figure shows a static balance measurement of the crankshaft assembly's center of mass and geometric center in the vertical direction. The Woodruff key is vertically positioned on the crankshaft assembly, and the first keyway in the locating block maintains the main body of the static balance measuring instrument in a horizontal position via the Woodruff key.
[0030] When the crankshaft assembly is in this position, it is statically balanced. However, due to manufacturing tolerances, a design standard for the amount of unbalance is specified: the weight used during measurement is a, and it is movable on either the left or right measuring rod. When the weight's movement range is between 0 ± b, if the left and right measuring rods remain horizontal and the crankshaft assembly does not roll, the crankshaft assembly's static balance in that direction is within the specified tolerance.
[0031] like Figure 5-Figure 7 This figure shows a static balance measurement of the crankshaft assembly, with the center of mass and geometric center connected horizontally. The Woodruff key is positioned horizontally on the crankshaft assembly, and the second keyway in the locating block maintains the main body of the static balance measuring instrument in a horizontal position via the Woodruff key.
[0032] When the crankshaft assembly is in this position, it reaches a static equilibrium state when a unilateral torque c*d is given. However, due to the manufacturing tolerance of the product, the design standard for the unbalance amount is specified: the weight of the weight is replaced with c during measurement and is moved on the torque balance side, that is, the weight moves on the left measuring rod during measurement. When the movement range of the weight is between d±e, the left measuring rod and the right measuring rod should remain in a horizontal position, and the crankshaft assembly should not roll. Place the front and rear crankshafts of the crankshaft assembly to be measured on the front and rear brackets of the measuring instrument, put the positioning block on the front crankshaft, put the weight on the measuring rod, and adjust the length of the lever arm. If the lever arm length is within the specified range to ensure that the crankshaft does not rotate in this position, it means that the static balance of the crankshaft assembly in this direction is within the specified tolerance range.
[0033] The crankshaft static balance measuring instrument described in this utility model can measure the static balance of a crankshaft assembly at two locations: vertically and horizontally, along the line connecting the center of mass and the geometric center. Furthermore, it is easy to replace weights of different weights, allowing the static balance of crankshaft assemblies of varying weights to be measured.
Claims
1. A crankshaft static balance measuring instrument, comprising a base (1), characterized in that: The base (1) is provided with a front bracket (2) and a rear bracket (3), a front crankshaft (4) and a rear crankshaft (5) of a component to be measured are placed on the front bracket (2) and the rear bracket (3), respectively, a positioning block (6) is installed on the front crankshaft (4), a left measuring rod (7) and a right measuring rod (8) are installed on the left and right sides of the positioning block (6), respectively, and a weight (11) is provided on the left measuring rod (7) or the right measuring rod (8).
2. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The upper side and the left side of the positioning block (6) are respectively provided with a first keyway (9) and a second keyway (10) for installing a semicircular key.
3. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The weight (11) can slide freely on the left measuring rod (7) and the right measuring rod (8).
4. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The inner hole of the positioning block (6) is a conical hole, which is assembled on the front end conical surface of the front crankshaft (4).
5. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The left measuring rod (7) and the right measuring rod (8) are both millimeter scales.
6. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The left measuring rod (7) and the right measuring rod (8) are respectively threadedly connected to the positioning block (6) through threaded holes on the left and right sides of the positioning block (6).
7. The crankshaft static balance measuring instrument according to claim 1, characterized in that: The upper ends of the front bracket (2) and the rear bracket (3) are designed as knife edges.