Engine compression ratio calculation method and device, measurement tool and vehicle

Abstract

The invention relates to the technical field of vehicles, in particular to an engine compression ratio calculation method and device, a measurement tool and a vehicle, and the method comprises the steps: obtaining design parameters and measurement parameters of a target cylinder of an engine; calculating a plurality of partial volumes of the target cylinder according to the design parameters and the measurement parameters; a compression ratio of the target cylinder is calculated from the plurality of partial volumes. Therefore, the problems that the compression ratio needs to be adjusted by disassembling and replacing pistons with different sizes when indexes are designed in related technologies, the adjusting method is low in efficiency and high in cost are solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a method, device, measuring tool and vehicle for calculating engine compression ratio. Background Art

[0002] As a key performance indicator of the engine, the compression ratio has a vital impact on the overall performance of the engine. It not only directly determines the engine's torque output, thermal efficiency and emission performance, but also indirectly affects the engine's fuel economy and service life. In theory, a higher compression ratio can bring higher thermal efficiency and stronger power output. This is because the higher the compression ratio, the greater the energy density generated by fuel combustion under the same conditions, thus releasing more energy per combustion.

[0003] However, the higher the compression ratio, the better. Too high a compression ratio will bring a series of problems, the most notable of which is that it is easy to cause engine knock. Knock is an abnormal combustion process that will produce unnecessary pressure waves in the combustion chamber, causing the engine to work unstably, and in severe cases, it may even damage engine components. In addition, too high a compression ratio will increase the heat load of the engine, reduce its durability, and may aggravate emission pollution problems.

[0004] Therefore, in the process of engine research and development, how to reasonably select the compression ratio is a challenging task. The method of adjusting the compression ratio in related technologies is usually based on theoretical calculations to determine the dimensions of key components such as pistons and connecting rods, and then use precision machining to ensure the manufacturing accuracy of these parts. After assembly, bench tests are required to verify the effectiveness of the selected compression ratio scheme. If the test results fail to meet the design goals, the engine needs to be disassembled and pistons or other related components of different sizes replaced to further adjust the compression ratio. As a result, each adjustment in related technologies requires reprocessing of parts and retesting for verification, and the adjustment method is inefficient and costly. Summary of the invention

[0005] The present application provides an engine compression ratio calculation method, device, measuring tool and vehicle to solve the problems of low efficiency and high cost in adjusting the compression ratio by dismantling the engine and replacing pistons of different sizes when designing related technical indicators.

[0006] The first aspect of the present application provides a method for calculating the compression ratio of an engine, comprising the following steps: obtaining design parameters and measurement parameters of a target cylinder of the engine; calculating multiple partial volumes of the target cylinder based on the design parameters and measurement parameters; and calculating the compression ratio of the target cylinder based on the multiple partial volumes.

[0007] Optionally, the plurality of partial volumes include a plurality of cylinder gasket volumes, power land volumes, ring groove back clearance volumes, stroke volumes, downstroke volumes, cylinder side combustion chamber volumes and total combustion volumes.

[0008] Optionally, calculating the compression ratio of the target cylinder according to the plurality of partial volumes includes: calculating the compression ratio of the target cylinder according to the stroke volume and the total combustion volume.

[0009] Optionally, the total combustion volume is the sum of the cylinder gasket volume, the fire land volume, the ring groove back clearance volume, the cylinder head combustion chamber volume, and the cylinder block side combustion chamber volume.

[0010] Optionally, the design parameters include at least one of cylinder gasket thickness, cylinder gasket inner hole diameter, fire bank diameter, fire bank height, piston ring groove bottom diameter, ring radial width, ring height and piston stroke, and the measurement parameters include at least one of cylinder bore diameter, downward piston top surface volume and cylinder head combustion chamber volume.

[0011] Optionally,

[0012] The calculation formula of cylinder gasket volume is: B5 = B4*B4*PI / 4*B3*a,

[0013] Among them, B5 represents the volume of the cylinder gasket, B3 represents the thickness of the cylinder gasket, B4 represents the inner diameter of the cylinder gasket, * represents multiplication, PI represents pi, / represents division, and a is a constant;

[0014] The calculation formula for the fire bank volume is:

[0015] B8=(B13*B13-B6*B6)*PI / 4*B7*b,

[0016] Among them, B8 represents the capacity of the fire bank, B13 represents the cylinder bore diameter, B6 represents the fire bank diameter, B7 represents the fire bank height, * represents multiplication, PI represents pi, / represents division, and b is a constant;

[0017] The calculation formula of the ring groove back clearance volume is:

[0018] B12=[(B13-B10*2)*(B13-B10*2)-B9*B9]*PI / 4*B7*c,

[0019] Among them, B12 represents the back clearance volume of the ring groove, B13 represents the cylinder bore diameter, B10 represents the radial width of the ring, B9 represents the bottom diameter of the piston ring groove, B7 represents the height of the firepower shore, * represents multiplication, PI represents pi, / represents division, and c is a constant;

[0020] The calculation formula for stroke volume is:

[0021] B15=B13*B13*PI / 4*B14*d,

[0022] Among them, B15 represents the stroke volume, B13 represents the cylinder bore diameter, B14 represents the stroke, * represents multiplication, PI represents pi, / represents division, and d is a constant;

[0023] The formula for calculating the downstroke volume is:

[0024] B17=B13*B13*PI / 4*5*e,

[0025] Among them, B17 represents the downstroke volume, B13 represents the cylinder bore diameter, * represents multiplication, PI represents pi, / represents division, and e is a constant;

[0026] The calculation formula for the combustion chamber volume on the cylinder side is:

[0027] B18 = B16-B17,

[0028] Among them, B18 represents the combustion chamber volume on the cylinder side, B16 represents the measured value of the downward piston top surface volume, and B17 represents the downward stroke volume.

[0029] The second aspect of the present application provides an engine compression ratio calculation device, including: an acquisition module, used to obtain design parameters and measurement parameters of a target cylinder of the engine; a first calculation module, used to calculate multiple partial volumes of the target cylinder based on the design parameters and measurement parameters; a second calculation module, used to calculate the compression ratio of the target cylinder based on the multiple partial volumes.

[0030] The third aspect of the present application provides a measuring tool, which is used to measure the measurement parameters of the target cylinder, and the measurement parameters are used in the engine compression ratio calculation method according to any one of claims 1 to 6, wherein the measuring tool comprises: a sinkage measuring tool and a storage calibration box, wherein the sinkage measuring tool comprises a counterweight seat, a top screw and a dial indicator; the storage calibration box comprises a storage box, a limit block and a calibration base plate; the dial indicator is zeroed in the storage calibration box, and the sinkage measuring tool is placed on the top surface of the cylinder body, and the top end of the dial indicator needle points to the fixed position of the piston, Turn the crankshaft to move the piston upward, find the top dead center of the piston through the maximum reading of the dial indicator, record the dial indicator reading of the top dead center of the piston, continue to rotate the crankshaft to make the piston downward, read the downward movement through the dial indicator, stop rotating the crankshaft, remove the sinking measurement tooling and place it in the storage and calibration box, seal the gap between the top of the piston and the cylinder liner, place a transparent glass plate, use a burette to drip distilled water into the cylinder, and at the same time push the transparent glass plate until the cylinder liner is filled with distilled water, read the volume of the dripped distilled water through the burette, and determine the volume of the top surface of the downward piston based on the volume of distilled water.

[0031] Optionally, the zero position of the dial indicator is that the top of the dial indicator needle is in the same plane as the bottom surface of the counterweight seat, and the fixed position is located on the axis of the piston pin and close to the plane of the cylinder liner.

[0032] A fourth aspect of the present application provides a vehicle, comprising an engine, wherein a compression ratio of the engine is calculated based on the engine compression ratio calculation method of the first aspect.

[0033] Therefore, this application includes the following beneficial effects:

[0034] The embodiment of the present application can calculate multiple partial volumes of the target cylinder through the design parameters and measurement parameters of the target cylinder of the engine, and calculate the compression ratio of the target cylinder according to the multiple partial volumes, so that different engines can output the actual compression ratio by simply inputting the corresponding measurement values, with high accuracy, strong practicality and simple operation. Therefore, the problems of the need to dismantle the machine and replace pistons of different sizes to adjust the compression ratio when designing indicators of related technologies are solved, and the adjustment method is inefficient and costly.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 A flowchart of a method for calculating an engine compression ratio according to an embodiment of the present application;

[0038] Figure 2 is an exemplary diagram of an engine compression ratio calculation device according to an embodiment of the present application;

[0039] Figure 3 This is an example diagram of a measuring tool provided according to an embodiment of the present application;

[0040] Figure 4 A schematic diagram of measuring piston sinking amount according to an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a piston sinking measurement tool provided according to an embodiment of the present application;

[0042] Figure 6 A schematic diagram of the storage of a piston sinking measurement tool provided according to an embodiment of the present application;

[0043] Figure 7 A schematic diagram of measuring the volume of a combustion chamber on the cylinder side according to an embodiment of the present application;

[0044] Figure 8 A schematic diagram of measuring the combustion chamber volume on the cylinder head side according to an embodiment of the present application.

[0045] Explanation of the reference numerals: 1- sinking measurement tool; 11- counterweight seat; 12- top screw; 13- dial indicator; 2- storage calibration box; 21- storage box; 22- limit block; 23- calibration base plate; 3- cylinder body; 4- piston; 5- transparent glass plate; 6- cylinder head; 61- combustion chamber. DETAILED DESCRIPTION

[0046] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0047] The following describes the engine compression ratio calculation method, device, measuring tool and vehicle of the embodiment of the present application with reference to the accompanying drawings. In view of the problems that the relevant technical design indicators mentioned in the above background technology need to dismantle the machine and replace pistons of different sizes to adjust the compression ratio, and the adjustment method is inefficient and costly, the present application provides an engine compression ratio calculation method. In this method, multiple partial volumes of the target cylinder are calculated by the design parameters and measurement parameters of the target cylinder of the engine, and the compression ratio of the target cylinder is calculated based on the multiple partial volumes, so that different engines only need to input corresponding measurement values ​​to output the actual compression ratio, with high accuracy, strong practicality and simple operation. As a result, the problems of low efficiency and high cost that the relevant technical design indicators need to be dismantled and replaced with pistons of different sizes to adjust the compression ratio are solved.

[0048] Specifically, Figure 1 A flow chart of a method for calculating the engine compression ratio provided in an embodiment of the present application.

[0049] like Figure 1 As shown, the engine compression ratio calculation method includes the following steps:

[0050] In step S101 , design parameters and measurement parameters of a target cylinder of the engine are obtained.

[0051] Among them, the design parameters and measurement parameters of the target cylinder of the engine will be described in detail below and will not be repeated here; the design parameters of the target cylinder of the engine can be obtained by referring to the design data to obtain the design parameters of the target cylinder; obtaining the measurement parameters of the target cylinder of the engine requires measuring the target cylinder, and the measurement is completed by the measuring tool proposed in this application. The measuring tool will be described in detail below and will not be repeated here.

[0052] It is understandable that the embodiment of the present application can obtain the design parameters of the target cylinder by consulting the design data, and use the measuring tool to measure the measurement parameters of the target cylinder.

[0053] In an embodiment of the present application, the design parameters include at least one of the cylinder gasket thickness, the cylinder gasket inner hole diameter, the fire bank diameter, the fire bank height, the piston ring groove bottom diameter, the ring radial width, the ring height and the piston stroke, and the measurement parameters include at least one of the cylinder hole diameter, the downward piston top surface volume and the cylinder head combustion chamber volume.

[0054] Among them, the cylinder gasket is used to seal the interface between the cylinder block and the cylinder head, and the thickness of the cylinder gasket has a direct impact on the compression ratio; the inner hole diameter of the cylinder gasket refers to the diameter of the inner hole on the cylinder gasket used to match the cylinder hole; the fire bank refers to the part of the cylinder head that contacts the top of the piston, and the fire bank diameter and the fire bank height are the size parameters of the fire bank; the piston ring groove bottom diameter refers to the diameter of the bottom of the groove on the piston for installing the piston ring; the radial width of the ring refers to the width of the piston ring along the radial direction, that is, the thickness of the piston ring; the ring height refers to the height of the piston ring, that is, the length of the piston ring along the axis of the cylinder; the piston stroke refers to the distance the piston moves from the top dead center to the bottom dead center; the cylinder bore diameter refers to the diameter inside the cylinder; the downward piston top surface volume is the volume formed between the top of the piston and the cylinder wall when the piston is at the bottom dead center; the cylinder head combustion chamber volume is the space volume between the top of the piston and the cylinder head when the piston is at the top dead center.

[0055] It can be understood that the design parameters included in the embodiments of the present application include at least one of the cylinder gasket thickness, cylinder gasket inner hole diameter, fire bank diameter, fire bank height, piston ring groove bottom diameter, ring radial width, ring height and piston stroke, which are basic parameters of the cylinder; the measurement parameters include at least one of the cylinder hole diameter, the volume of the downward piston top surface and the cylinder head combustion chamber volume, all of which need to be measured and obtained.

[0056] In step S102 , a plurality of partial volumes of the target cylinder are calculated according to the design parameters and the measured parameters.

[0057] It can be understood that, in the embodiment of the present application, multiple partial volumes of the target cylinder can be calculated based on the acquired design parameters and the measured parameters, wherein the multiple partial volumes will be described in detail below, specifically as follows:

[0058] In an embodiment of the present application, the plurality of partial volumes include a plurality of cylinder gasket volumes, a fire land volume, a ring groove back clearance volume, a stroke volume, a downstroke volume, a cylinder side combustion chamber volume and a total combustion volume.

[0059] Among them, the cylinder gasket volume refers to the volume formed by the cylinder gasket between the cylinder head and the cylinder block; the fire bank volume refers to the space occupied by the fire bank on the cylinder head; the ring groove back clearance volume refers to the volume formed by the gap between the back of the piston ring in its groove and the piston; the stroke volume refers to the volume swept by the piston in a complete stroke, that is, the stroke from the top dead center to the bottom dead center; the downstroke volume refers to the volume swept by the piston when it moves from the top dead center to the bottom dead center; the cylinder side combustion chamber volume refers to the volume of a part of the combustion chamber formed by the combustion chamber in the cylinder body; the total combustion volume refers to the total volume between the top of the piston and the cylinder head when the piston is at the top dead center.

[0060] It can be understood that in the embodiment of the present application, the cylinder gasket volume, the power shore volume, the ring groove back clearance volume, the stroke volume, the downward stroke volume, the cylinder side combustion chamber volume and the total combustion volume constitute multiple partial volumes.

[0061] In the embodiment of the present application, the total combustion volume is the sum of the cylinder gasket volume, the fire land volume, the ring groove back clearance volume, the cylinder head combustion chamber volume, and the cylinder body side combustion chamber volume.

[0062] It can be understood that the total combustion volume in the embodiment of the present application can be calculated using the cylinder gasket volume, the power shore volume, the annular groove back clearance volume, the cylinder head combustion chamber volume, and the cylinder side combustion chamber volume. The calculation formula is B20=B19+B18+B5+B8+B12, wherein B20 represents the total combustion volume, B19 represents the cylinder head combustion chamber volume, B18 represents the cylinder side combustion chamber volume, B5 represents the cylinder gasket volume, B8 represents the power shore volume, and B12 represents the annular groove back clearance volume.

[0063] In step S103, the compression ratio of the target cylinder is calculated based on the plurality of partial volumes.

[0064] It is understandable that the embodiment of the present application can calculate the compression ratio of the target cylinder according to multiple partial volumes, and the calculation method will be described in detail below, specifically as follows:

[0065] In an embodiment of the present application, calculating the compression ratio of the target cylinder according to the plurality of partial volumes includes: calculating the compression ratio of the target cylinder according to the stroke volume and the total combustion volume.

[0066] Among them, the calculation formula for calculating the compression ratio of the target cylinder based on the stroke volume and the total combustion volume is B21=(B20+B15) / B20, B21 represents the compression ratio of the target cylinder, B20 represents the total combustion volume, and B15 represents the stroke volume.

[0067] It can be understood that the compression ratio of the target cylinder in the embodiment of the present application is calculated based on the stroke volume and the total combustion volume through the formula B21=(B20+B15) / B20.

[0068] In the embodiments of the present application,

[0069] The calculation formula of cylinder gasket volume is: B5 = B4*B4*PI / 4*B3*a,

[0070] Among them, B5 represents the volume of the cylinder gasket, B3 represents the thickness of the cylinder gasket, B4 represents the inner diameter of the cylinder gasket, * represents multiplication, PI represents pi, / represents division, and a is a constant;

[0071] The calculation formula for the fire bank volume is:

[0072] B8=(B13*B13-B6*B6)*PI / 4*B7*b,

[0073] Among them, B8 represents the capacity of the fire bank, B13 represents the cylinder bore diameter, B6 represents the fire bank diameter, B7 represents the fire bank height, * represents multiplication, PI represents pi, / represents division, and b is a constant;

[0074] The calculation formula of the ring groove back clearance volume is:

[0075] B12=[(B13-B10*2)*(B13-B10*2)-B9*B9]*PI / 4*B7*c,

[0076] Among them, B12 represents the back clearance volume of the ring groove, B13 represents the cylinder bore diameter, B10 represents the radial width of the ring, B9 represents the bottom diameter of the piston ring groove, B7 represents the height of the firepower shore, * represents multiplication, PI represents pi, / represents division, and c is a constant;

[0077] The calculation formula for stroke volume is:

[0078] B15=B13*B13*PI / 4*B14*d,

[0079] Among them, B15 represents the stroke volume, B13 represents the cylinder bore diameter, B14 represents the stroke, * represents multiplication, PI represents pi, / represents division, and d is a constant;

[0080] The formula for calculating the downstroke volume is:

[0081] B17=B13*B13*PI / 4*5*e,

[0082] Among them, B17 represents the downstroke volume, B13 represents the cylinder bore diameter, * represents multiplication, PI represents pi, / represents division, and e is a constant;

[0083] The calculation formula for the combustion chamber volume on the cylinder side is:

[0084] B18 = B16-B17,

[0085] Among them, B18 represents the combustion chamber volume on the cylinder side, B16 represents the measured value of the downward piston top surface volume, and B17 represents the downward stroke volume.

[0086] It can be understood that the embodiments of the present application can calculate the cylinder gasket volume, the power shore volume, the annular groove back clearance volume, the stroke volume, the downstroke volume and the cylinder side combustion chamber volume by the above formula, wherein, in one engine, the cylinder gasket volume calculation formula of the cylinder is the same; the power shore volume, the annular groove back clearance volume, the stroke volume, the downstroke volume and the cylinder side combustion chamber volume calculation formula are similar but not the same, the difference is that the parameters in the formula are the design parameters or measurement parameters of the cylinder itself.

[0087] For example, suppose the parameters starting with B are the parameters of the first cylinder of the engine, the parameters starting with C are the parameters of the second cylinder of the engine, and the parameters starting with D are the parameters of the third cylinder of the engine. In the above description, the cylinder gasket volume calculation formula is the same. Therefore, the cylinder gasket volume calculation formula for the first cylinder is: B5=B4*B4*PI / 4*B3*a, and the cylinder gasket volume calculation formula for the second cylinder and the third cylinder is also B5=B4*B4*PI / 4*B3*a; the calculation formulas for the power shore volume, the ring groove back clearance volume, the stroke volume, the downward stroke volume and the cylinder side combustion chamber volume are similar but not the same. The difference is that the parameters in the formula are the cylinder's own Design parameters or measurement parameters, taking the fire shore volume as an example, the calculation formula for the fire shore volume of the first cylinder is: B8 = (B13*B13-B6*B6)*PI / 4*B7*0.001, the calculation formula for the fire shore volume of the second cylinder and the third cylinder is the design parameters or measurement parameters of the cylinder itself. Therefore, the calculation formula for the fire shore volume of the second cylinder is C8 = (C13*C13-C6*C6)*PI / 4*C7*0.001, the calculation formula for the fire shore volume of the third cylinder is D8 = (D13*D13-D6*D6)*PI / 4*D7*0.001, and the remaining parameter formulas are similar.

[0088] According to the engine compression ratio calculation method proposed in the embodiment of the present application, multiple partial volumes of the target cylinder can be calculated through the design parameters and measurement parameters of the target cylinder of the engine, and the compression ratio of the target cylinder can be calculated based on the multiple partial volumes, so that different engines can output the actual compression ratio by only inputting the corresponding measurement values, with high accuracy, strong practicality and easy operation.

[0089] The method for calculating the engine compression ratio proposed in the embodiment of the present application is further described below through a specific example.

[0090] The technical solution of this embodiment is as follows:

[0091] The compression ratio calculation method can be roughly divided into the following steps:

[0092] Obtain design parameters: First, you need to obtain basic parameters such as cylinder gasket thickness, cylinder gasket inner hole diameter, fire bank diameter, fire bank height, piston TOP ring groove bottom diameter, TOP ring radial width, TOP ring height and piston stroke.

[0093] Measurement parameters: The cylinder bore diameter, the 5mm downward piston top volume measurement value and the cylinder head combustion chamber volume need to be measured.

[0094] Calculate partial volumes: It is necessary to calculate the cylinder gasket volume, fire bank volume, TOP ring groove back clearance volume, stroke volume, 5mm downward stroke volume, cylinder side combustion chamber volume and total combustion volume.

[0095] Finally, the compression ratio is calculated. The compression ratio calculation method has been summarized in Table 1, which is shown below:

[0096] Table 1: Compression ratio calculation method and parameter formula

[0097]

[0098]

[0099] In Table 1, taking the calculation of cylinder gasket volume (ml) as an example, a formula like "B4*B4*PI / 4*B3*0.001" is used. B4 represents the value of row 4 in column B, * represents multiplication, PI is pi, and / is division.

[0100] For example, to calculate the compression ratio, the formula "(B20+B15) / B20" or a similar formula is used to calculate the compression ratio, where B20 represents the value in row 20 of column B, i.e., the total combustion volume, and B15 represents the stroke volume.

[0101] It should be noted that the calculation formulas in the table are relatively complex and involve multiple variables and parameters, which need to be replaced and calculated based on specific measured values ​​and actual conditions.

[0102] From the above, it can be concluded that the technical solution of this embodiment mainly includes the following steps:

[0103] 1. Prepare measuring equipment: This measurement method uses a high-precision titration instrument to ensure the accuracy of the measurement results.

[0104] 2. Measure the partial combustion chamber volume of the cylinder block (Vc1): Place the piston protrusion measuring tool on the top surface of the engine cylinder block, rotate the crankshaft to find the top dead center of the piston, rotate the crankshaft again to lower the piston 5mm, measure the volume at this time, subtract the volume of the 5mm cylinder (diameter is the cylinder diameter), and obtain the partial combustion chamber volume of the cylinder block (Vc1).

[0105] 3. Measure the partial combustion chamber volume of the cylinder head (Vc2): With the help of a glass plate, use a high-precision titration instrument to measure and obtain the partial combustion chamber volume of the cylinder head (Vc2).

[0106] 4. Calculate the compression ratio: Add the combustion chamber volume of the cylinder block (Vc1) and the combustion chamber volume of the cylinder head (Vc2) to get the combustion chamber volume Vc. Substitute Vc into the calculation formula to get the actual compression ratio of the engine.

[0107] In the above process, the measured values ​​are obtained using a measuring tool. The measuring tool and the obtaining method will be described in detail below and will not be repeated here.

[0108] Next, the engine compression ratio calculation device proposed in accordance with the embodiment of the present application will be described with reference to the accompanying drawings.

[0109] Figure 2 It is a block diagram of an engine compression ratio calculation device according to an embodiment of the present application.

[0110] like Figure 2 As shown, the engine compression ratio calculation device 10 includes: an acquisition module 201, a first calculation module 202 and a second calculation module 203.

[0111] Among them, the acquisition module 201 is used to obtain the design parameters and measurement parameters of the target cylinder of the engine; the first calculation module 202 is used to calculate multiple partial volumes of the target cylinder according to the design parameters and measurement parameters; the second calculation module 203 is used to calculate the compression ratio of the target cylinder according to the multiple partial volumes.

[0112] In an embodiment of the present application, the plurality of partial volumes include a plurality of cylinder gasket volumes, a fire land volume, a ring groove back clearance volume, a stroke volume, a downstroke volume, a cylinder side combustion chamber volume and a total combustion volume.

[0113] In the embodiment of the present application, the total combustion volume is the sum of the cylinder gasket volume, the fire land volume, the ring groove back clearance volume, the cylinder head combustion chamber volume, and the cylinder body side combustion chamber volume.

[0114] In an embodiment of the present application, the design parameters include at least one of the cylinder gasket thickness, the cylinder gasket inner hole diameter, the fire bank diameter, the fire bank height, the piston ring groove bottom diameter, the ring radial width, the ring height and the piston stroke, and the measurement parameters include at least one of the cylinder hole diameter, the downward piston top surface volume and the cylinder head combustion chamber volume.

[0115] In the embodiment of the present application, the second calculation module 203 is further used to calculate the compression ratio of the target cylinder according to the stroke volume and the total combustion volume.

[0116] In the embodiments of the present application,

[0117] The calculation formula of cylinder gasket volume is: B5 = B4*B4*PI / 4*B3*a,

[0118] Among them, B5 represents the volume of the cylinder gasket, B3 represents the thickness of the cylinder gasket, B4 represents the inner diameter of the cylinder gasket, * represents multiplication, PI represents pi, / represents division, and a is a constant;

[0119] The calculation formula for the fire bank volume is:

[0120] B8=(B13*B13-B6*B6)*PI / 4*B7*b,

[0121] Among them, B8 represents the capacity of the fire bank, B13 represents the cylinder bore diameter, B6 represents the fire bank diameter, B7 represents the fire bank height, * represents multiplication, PI represents pi, / represents division, and b is a constant;

[0122] The calculation formula of the ring groove back clearance volume is:

[0123] B12=[(B13-B10*2)*(B13-B10*2)-B9*B9]*PI / 4*B7*c,

[0124] Among them, B12 represents the back clearance volume of the ring groove, B13 represents the cylinder bore diameter, B10 represents the radial width of the ring, B9 represents the bottom diameter of the piston ring groove, B7 represents the height of the firepower shore, * represents multiplication, PI represents pi, / represents division, and c is a constant;

[0125] The calculation formula for stroke volume is:

[0126] B15=B13*B13*PI / 4*B14*d,

[0127] Among them, B15 represents the stroke volume, B13 represents the cylinder bore diameter, B14 represents the stroke, * represents multiplication, PI represents pi, / represents division, and d is a constant;

[0128] The formula for calculating the downstroke volume is:

[0129] B17=B13*B13*PI / 4*5*e,

[0130] Among them, B17 represents the downstroke volume, B13 represents the cylinder bore diameter, * represents multiplication, PI represents pi, / represents division, and e is a constant;

[0131] The calculation formula for the combustion chamber volume on the cylinder side is:

[0132] B18 = B16-B17,

[0133] Among them, B18 represents the combustion chamber volume on the cylinder side, B16 represents the measured value of the downward piston top surface volume, and B17 represents the downward stroke volume.

[0134] It should be noted that the aforementioned explanation of the engine compression ratio method embodiment is also applicable to the engine compression ratio device of this embodiment, and will not be repeated here.

[0135] According to the engine compression ratio device proposed in the embodiment of the present application, the design parameters and measurement parameters of the target cylinder of the engine are obtained through an acquisition module, and a first calculation module is used to calculate multiple partial volumes of the target cylinder together with the design parameters and the measurement parameters. Finally, the compression ratio of the target cylinder is calculated using the second calculation module, thereby achieving the output of the actual compression ratio of different engines by only inputting the corresponding measurement values, with high accuracy, strong practicality and easy operation.

[0136] The present application also provides a measuring tool, which is used to measure the measurement parameters of the target cylinder, and the measurement parameters are used in the engine compression ratio calculation method, such as Figure 3 As shown, the measuring tool 20 includes: a sinkage measuring tool 1 and a storage calibration box 2, wherein:

[0137] The sinking measurement tool 1 includes a counterweight seat 11, a top screw 12 and a dial indicator 13; the storage calibration box 2 includes a storage box 21, a limit block 22 and a calibration base plate 23.

[0138] In an embodiment of the present application, the dial indicator 13 is calibrated to zero in the storage and calibration box 2, and the sinking measurement tool 1 is placed on the top surface of the cylinder body, with the top of the needle of the dial indicator 13 pointing to the fixed position of the piston. The crankshaft is rotated to move the piston upward, and the top dead center of the piston is found by the maximum reading of the dial indicator 13. The dial indicator reading at the top dead center of the piston is recorded, and the crankshaft is continued to be rotated to move the piston downward. The downward movement is read by the dial indicator 13, and the crankshaft is stopped. The sinking measurement tool 1 is removed and placed in the storage and calibration box 2, the gap between the top of the piston and the cylinder liner is sealed, a transparent glass plate is placed, and a burette is used to drip distilled water into the cylinder barrel. At the same time, the transparent glass plate is pushed until the cylinder liner is filled with distilled water, and the volume of the dripped distilled water is read by the burette. The volume of the downward piston top surface is determined according to the volume of distilled water.

[0139] It can be understood that the embodiment of the present application measures the volume of the top surface of the downward piston through the measuring tool 20, places the sinking tool 1 on the top surface of the cylinder body, rotates the crankshaft to adjust the piston, uses the dial indicator 13 to read the position of the maximum and minimum readings, finds the top dead center and the bottom dead center of the piston, seals the gap between the top of the piston and the cylinder liner, places a transparent glass plate, and uses a burette to drip distilled water into the cylinder while pushing the transparent glass plate until the cylinder liner is filled with distilled water, and reads the volume of the distilled water dripped into the burette, which is the volume of the top surface of the downward piston.

[0140] In the embodiment of the present application, the zero position of the dial indicator 13 is when the top of the needle of the dial indicator 13 is in the same plane as the bottom surface of the counterweight seat 11, and the fixed position is located on the axis of the piston pin and close to the plane of the cylinder sleeve.

[0141] Among them, the piston pin axis refers to the center line of the piston pin. The piston pin is also called the connecting rod pin or wrist pin, and its main function is to connect the piston and the connecting rod.

[0142] It can be understood that in the embodiment of the present application, when the top of the needle of the dial indicator 13 is in the same plane as the bottom surface of the counterweight seat, the dial indicator 13 should display zero, and the fixed position of the dial indicator 13 should be along the axial direction of the piston pin and should be as close to the plane of the cylinder liner as possible to ensure the accuracy of the measurement.

[0143] According to the measuring tool proposed in the embodiment of the present application, by using the sinking measurement tool and the storage calibration box and the components such as the counterweight seat, top screw, dial indicator, storage box, limit block and calibration base plate therein, the downward piston top surface volume measurement value, the cylinder head combustion chamber volume and other parameters can be simply and efficiently measured. In conjunction with other design parameters of the target cylinder, multiple partial volumes of the target cylinder can be calculated and finally the compression ratio of the target cylinder can be calculated, thereby achieving different engines Only need to input the corresponding measurement value to output the actual compression ratio, with high accuracy, strong practicality and easy operation.

[0144] The measuring tool proposed in the embodiment of the present application is described in detail below through a specific embodiment.

[0145] As shown in the figure, Figure 4 Schematic diagram of measuring the piston sinking amount in this embodiment; Figure 5 Schematic diagram of the piston sinking measurement tooling of this embodiment; Figure 6 Schematic diagram of the piston sinking measurement tooling of this embodiment; Figure 7 Schematic diagram of measuring the combustion chamber volume on the cylinder side of this embodiment; Figure 8 : is a schematic diagram of measuring the combustion chamber volume on the cylinder head side of this embodiment, and the following is a detailed description of obtaining the measured value:

[0146] Cylinder diameter: Use an inside micrometer to measure the top (5 mm from the top surface of the cylinder body), middle (middle of the cylinder liner), and bottom (5 mm from the bottom of the cylinder liner) sections of the cylinder liner. Take 3 groups of measurements on each section (measured 120 degrees apart). First calculate the average value of each section, and then calculate the average value of the three sections as the cylinder diameter.

[0147] 5mm downward piston top volume measurement value:

[0148] It is difficult to measure the combustion chamber volume on the cylinder side directly. The piston of some engines will protrude from the top of the cylinder, making it impossible to measure directly. Therefore, a calculation method is used to obtain the volume. The 5mm down piston top volume measurement value includes the volume of the 5mm high cylinder and the combustion chamber volume on the cylinder side.

[0149] First, use the sinking measurement tool 1 to measure the piston top dead center and move it down 5mm, and then use the water volume method to measure with the help of the transparent glass plate 5. The sinking measurement tool includes a counterweight seat 11, a top screw 12 and a dial indicator 13. Before measurement, the dial indicator 13 is calibrated to zero in the storage calibration box 2. The zero position of the dial indicator is when the top of the dial indicator needle is in the same plane as the bottom surface of the counterweight seat 11. The above-mentioned storage calibration box 2 includes a storage box 21, a limit block 22 and a calibration base plate 23. After the dial indicator 13 is calibrated to zero, place the sinking measurement tool 1 on the top surface of the cylinder body 3, as shown in FIG. Figure 1 As shown, the top of the needle points to the fixed position of the piston 4. The above-mentioned fixed position is located on the axis of the piston pin and close to the small plane of the cylinder liner. The above-mentioned fixed position is placed to avoid errors caused by the replacement of the piston bearing surface when the piston moves upward or downward, and the swing of the piston around the axis of the piston pin. After placing the sinking measurement tool 1, turn the crankshaft to make the piston 4 move upward, and find the top dead center of the piston through the maximum reading of the dial indicator. The reading at this time is the piston protrusion or sinking amount. Record the dial indicator reading at the top dead center of the piston, and then continue to rotate the crankshaft to make the piston 4 move downward. Read 5mm downward through the dial indicator, stop rotating the crankshaft, remove the sinking measurement tool 1 and place it in the storage calibration box 2. Use Vaseline to seal the gap between the top of the piston 4 and the cylinder liner, and apply Vaseline around the cylinder hole on the top surface of the cylinder body 3. Place a transparent glass plate 5, as shown Figure 7 As shown. Then use a burette to drip distilled water into the cylinder, and at the same time push the transparent glass plate 5 until the cylinder is full of distilled water. The volume of distilled water dripped in through the burette is the volume of the top surface of the 5mm downward piston. Use the above method to measure the volume of the top surface of the 5mm downward piston of each cylinder hole in turn, and record it in the corresponding position of the table.

[0150] Cylinder head combustion chamber volume: First, use the tool to seal the injection hole, turn the cylinder head 6 upside down with the top facing up, apply vaseline around the combustion chamber on the bottom of the cylinder head 6, and place a transparent glass plate 5. Figure 6 As shown. Then use a burette to drip distilled water into the combustion chamber, and push the transparent glass plate 5 at the same time until the combustion chamber is full of distilled water. The volume of distilled water dripped in through the burette is the cylinder head combustion chamber volume. Use the above method to measure the cylinder head combustion chamber volume of each cylinder in turn, and record it in the corresponding position of the table.

[0151] Enter the theoretical value and the measured value into an Excel table to get the actual compression ratio. The theoretical value is a fixed value that does not need to be changed once it is entered (it only needs to be changed when the design value changes). For different engines, you only need to enter the corresponding measured value to output the actual compression ratio. This method has the advantages of high accuracy (by directly measuring the cylinder diameter and combustion chamber volume, the engine compression ratio can be calculated more accurately), strong practicality (applicable to various types of engines and has a wide range of applicability), and simple operation (the required parameters are easy to obtain and no manual calculation is required).

[0152] It should be noted that the aforementioned explanation of the engine compression ratio method embodiment is also applicable to the measuring tool of this embodiment, and the explanation of the measuring tool embodiment here is also applicable to the aforementioned engine compression ratio method. The two are mutually contrasted and complement each other, and will not be repeated here.

[0153] An embodiment of the present application also provides a vehicle, including an engine, wherein the compression ratio of the engine is calculated based on the above-mentioned engine compression ratio calculation method.

[0154] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0155] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0156] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0157] It should be understood that the various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, the steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0158] A person of ordinary skill in the art may understand that all or part of the steps carried by the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the above-mentioned program may be stored in a computer-readable storage medium, which, when executed, includes one of the steps of the method embodiment or a combination thereof.

[0159] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for calculating engine compression ratio, characterized in that: The following steps are involved: Obtaining design parameters and measurement parameters of a target cylinder of an engine; calculating a plurality of partial volumes of the target cylinder based on the design parameters and the measured parameters; A compression ratio of the target cylinder is calculated based on the plurality of partial volumes.

2. The method for calculating the engine compression ratio according to claim 1, characterized in that: The plurality of partial volumes include a plurality of cylinder gasket volumes, power land volumes, ring groove back clearance volumes, stroke volumes, downstroke volumes, cylinder side combustion chamber volumes and total combustion volumes.

3. The method for calculating the engine compression ratio according to claim 2, characterized in that: The calculating the compression ratio of the target cylinder according to the plurality of partial volumes comprises: A compression ratio of the target cylinder is calculated based on the stroke volume and the total combustion volume.

4. The method for calculating the engine compression ratio according to claim 2 or 3, characterized in that: The total combustion volume is the sum of the cylinder gasket volume, the fire land volume, the ring groove back clearance volume, the cylinder head combustion chamber volume, and the cylinder body side combustion chamber volume.

5. The method for calculating the engine compression ratio according to claim 2, characterized in that: The design parameters include at least one of the cylinder gasket thickness, cylinder gasket inner hole diameter, fire bank diameter, fire bank height, piston ring groove bottom diameter, ring radial width, ring height and piston stroke; the measurement parameters include at least one of the cylinder bore diameter, the volume of the descending piston top surface and the volume of the cylinder head combustion chamber.

6. The method for calculating the engine compression ratio according to claim 5, characterized in that: The calculation formula of the cylinder gasket volume is: B5 = B4*B4*PI / 4*B3*a, Wherein, B5 represents the volume of the cylinder gasket, B3 represents the thickness of the cylinder gasket, B4 represents the inner hole diameter of the cylinder gasket, * represents multiplication, PI represents pi, / represents division, and a is a constant; The calculation formula of the fire bank volume is: B8=(B13*B13-B6*B6)*PI / 4*B7*b, Wherein, B8 represents the capacity of the fire bank, B13 represents the cylinder bore diameter, B6 represents the fire bank diameter, B7 represents the fire bank height, * represents multiplication, PI represents pi, / represents division, and b is a constant; The calculation formula of the annular groove back clearance volume is: B12=[(B13-B10*2)*(B13-B10*2)-B9*B9]*PI / 4*B7*c, Wherein, B12 represents the back clearance volume of the ring groove, B13 represents the cylinder bore diameter, B10 represents the radial width of the ring, B9 represents the bottom diameter of the piston ring groove, B7 represents the height of the fire land, * represents multiplication, PI represents pi, / represents division, and c is a constant; The calculation formula of the stroke volume is: B15=B13*B13*PI / 4*B14*d, Wherein, B15 represents the stroke volume, B13 represents the cylinder bore diameter, B14 represents the stroke, * represents multiplication, PI represents pi, / represents division, and d is a constant; The calculation formula of the downward stroke volume is: B17=B13*B13*PI / 4*5*e, Wherein, B17 represents the downstroke volume, B13 represents the cylinder bore diameter, * represents multiplication, PI represents pi, / represents division, and e is a constant; The calculation formula of the cylinder side combustion chamber volume is: B18 = B16-B17, Among them, B18 represents the combustion chamber volume on the cylinder side, B16 represents the measured value of the downward piston top surface volume, and B17 represents the downward stroke volume.

7. An engine compression ratio calculation device, characterized in that: include: An acquisition module, used for acquiring design parameters and measurement parameters of a target cylinder of the engine; a first calculation module, configured to calculate a plurality of partial volumes of the target cylinder according to the design parameters and the measurement parameters; A second calculation module is used to calculate the compression ratio of the target cylinder according to the multiple partial volumes.

8. A measuring tool, characterized in that: The measuring tool is used to measure the measurement parameters of the target cylinder, and the measurement parameters are used in the engine compression ratio calculation method according to any one of claims 1 to 6, wherein the measuring tool comprises: a sinking measurement tool and a storage calibration box, wherein: The sinking measurement tool comprises a counterweight seat, a top screw and a dial indicator; The storage calibration box comprises a storage box, a limit block and a calibration base plate; The dial indicator is calibrated to zero in the storage calibration box, and the sinking measurement tool is installed on the top surface of the cylinder body, with the top of the dial indicator needle pointing to the fixed position of the piston, the crankshaft is rotated to make the piston move upward, and the top dead center of the piston is found by the maximum dial indicator reading, and the dial indicator reading at the top dead center of the piston is recorded, and the crankshaft is continued to be rotated to make the piston move downward, and the downward movement is read by the dial indicator, and the crankshaft is stopped. The sinking measurement tool is removed and placed in the storage calibration box, the gap between the top of the piston and the cylinder sleeve is sealed, and a transparent glass plate is placed, and distilled water is dripped into the cylinder using a burette, and the transparent glass plate is pushed at the same time until the cylinder sleeve is filled with distilled water, and the volume of the dripped distilled water is read by the burette, and the volume of the top surface of the downward piston is determined according to the volume of distilled water.

9. The measuring tool according to claim 8, characterized in that: The zero position of the dial indicator is that the top of the dial indicator needle is in the same plane as the bottom surface of the counterweight seat, and the fixed position is located on the axis of the piston pin and close to the plane of the cylinder sleeve.

10. A vehicle, characterized in that: Comprising an engine, wherein the compression ratio of the engine is calculated based on the engine compression ratio calculation method according to any one of claims 1-6.

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