CN210440094U

CN210440094U - Distribution camshaft for improving low-speed performance of diesel engine

Info

Publication number: CN210440094U
Application number: CN201920970085.4U
Authority: CN
Inventors: 刘英华; 耿文耀; 李建惠; 安玉静; 刘云霞; 赵祎; 王学兵; 黄兰杰; 温艳丽; 李全帅
Original assignee: Hebei Huabei Diesel Engine Co Ltd
Current assignee: Hebei Huabei Diesel Engine Co Ltd
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2020-05-01
Anticipated expiration: 2029-06-26

Abstract

The utility model relates to an improve distribution camshaft of diesel engine low-speed performance, belong to engine part technical field, an improve distribution camshaft of diesel engine low-speed performance, set up 8 air intake cams and 8 exhaust cams on the camshaft, the camshaft of 8 air intake cams and 8 exhaust cams corresponds 1 ~ 8 cylinders in proper order, four air intake cams wherein have two lift molded lines to two lift molded lines form main cam and supplementary cam respectively, the phase difference on two lift molded lines summit α angle, four other air intake cams are the single lift molded lines, the utility model discloses improve distribution camshaft, distribution camshaft's part air intake cam's molded lines change into the structure of two lift molded lines, the molded lines of remaining part air intake cam do not change, distribution camshaft after the improvement can improve low-speed district cylinder inflation coefficient, improves the air input when the diesel engine low-speed operation to effectively improve diesel engine low temperature performance, improve the diesel engine low-speed torque.

Description

Distribution camshaft for improving low-speed performance of diesel engine

Technical Field

The utility model relates to an improve distribution camshaft of diesel engine low-speed performance belongs to engine part technical field.

Background

The valve camshaft is an important part of the engine, and determines the combustion utilization performance of the engine for fuel. In a conventional valve-actuating camshaft currently used, for example, an 8-cylinder engine, 8 intake cams in total, E1, E2, E3, E4, E5, E6, E7 and E8, are all in the same lift, and 8 exhaust cams in total, a1, a2, A3, a4, a5, A6, a7 and A8, are also in the same lift.

Originally, in order to meet the plateau power of the whole machine, the supercharger reduces the supercharging pressure of a low-speed area during design, solves the problems of overspeed and high exhaust temperature of the plateau supercharger and meets the design index requirements. However, the matched conventional distribution camshaft can reduce the low-speed charging efficiency, the excess air coefficient and the intercooled pressure, so that the problem of insufficient low-speed torque is caused.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an improve distribution camshaft of diesel engine low-speed performance solves above-mentioned technical problem.

In order to realize the purpose, the utility model discloses a technical scheme is:

a distribution camshaft for improving low-speed performance of a diesel engine is provided with 8 intake cams and 8 exhaust cams, the camshafts of the 8 intake cams and the 8 exhaust cams sequentially correspond to No. 1-8 cylinders, four of the intake cams are provided with two lift type lines, the two lift type lines respectively form a main cam and an auxiliary cam, the phase difference of the vertexes of the two lift type lines is α degrees, and the other four intake cams are single-lift type lines.

The utility model discloses technical scheme's further improvement lies in: the lift of the two lift profiles is 1.038mm and 8.4mm, respectively.

The technical proposal of the utility model is further improved in that the α angle of the phase difference of the two lift type lines is 112.5 degrees.

The utility model discloses technical scheme's further improvement lies in: the intake cams corresponding to the No. 3 cylinder, the No. 4 cylinder, the No. 6 cylinder, and the No. 8 cylinder have two lift profiles.

The utility model discloses technical scheme's further improvement lies in: the cam of the cam shaft from one end to the other end is respectively an exhaust cam of No. 8 cylinder, an intake cam of No. 4 cylinder, an intake cam of No. 8 cylinder, an exhaust cam of No. 4 cylinder, an exhaust cam of No. 7 cylinder, an intake cam of No. 3 cylinder, an intake cam of No. 7 cylinder, an exhaust cam of No. 3 cylinder, an exhaust cam of No. 6 cylinder, an intake cam of No. 2 cylinder, an exhaust cam of No. 5 cylinder, an intake cam of No. 1 cylinder, an intake cam of No. 5 cylinder and an exhaust cam of No. 1 cylinder.

Since the technical scheme is used, the utility model discloses the technological effect who gains has:

the utility model discloses improved distribution camshaft, distribution camshaft's part admission cam's molded lines change into the structure of two lift molded lines, and remaining part's admission cam's molded lines are unchangeable, and distribution camshaft after the improvement can improve low-speed district cylinder inflation coefficient, improves the air input when the diesel engine low-speed moves to effectively improve diesel engine low temperature performance, improve diesel engine low-speed moment of torsion.

The two-lift intake cam of the utility model has the lift of one cam of 1.038mm, which opens the intake valve at low speed, and the cylinder pressure is higher at the moment, thus improving the intake pressure; the other cam has a lift of 8.4mm and operates in the main intake phase with the intake valve reopened, which increases the intake charge.

The utility model discloses can improve diesel engine low temperature performance, improve the diesel engine low-speed moment of torsion, solve the not enough problem of moment of torsion.

Drawings

FIG. 1 is a schematic view of the distribution camshaft of the present invention;

FIG. 2 is a schematic view taken from A-A in FIG. 1;

FIG. 3 is a schematic view of FIG. 1 taken along line B-B;

FIG. 4 is a schematic view taken along line C-C of FIG. 1;

fig. 5 is a schematic view from direction D-D in fig. 1.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and specific embodiments:

the utility model discloses an improve distribution camshaft of diesel engine low-speed performance is the improvement to current distribution camshaft. The following are specific examples:

the utility model discloses a distribution camshaft improves diesel engine low-speed performance through the structure that improves air intake cam. The utility model discloses mainly use 8 jar diesel engines to carry out the structural description as the example. As shown in FIG. 1, the camshaft is provided with 8 intake cams and 8 exhaust cams, and the camshafts of the 8 intake cams and the 8 exhaust cams sequentially correspond to No. 1-8 cylinders.

The utility model discloses an improvement lies in setting up four intake cams therein to the structure that has two lift style molded lines, these two lift style molded lines form main cam and auxiliary cam respectively, and four intake cams structures are unchangeable, still are single lift style molded lines, the lift range of two lift style molded lines is 1.038mm and 8.4mm respectively, specifically the lift range of main cam is 8.4mm, the lift range of auxiliary cam is 1.038mm, the summit phase difference α angle setting of two lift style molded lines, this angle is adjusted according to actual demand and different diesel engine's performance, in this embodiment, the phase difference α angle of the summit of two lift style molded lines that provides is 112.5 degrees, to in one of them intake cam that has two lift style molded lines, in the course of operation, make the intake valve open during the cam low speed of 1.038mm, cylinder pressure is higher at this moment, improve intake pressure, the intake valve closes the back, the main stage of admitting air during operation of the cam of 8.4mm, the lift valve is opened again, and the lift range of charge improves and admits air.

In a specific implementation, the lift profile parameters of the main cam and the auxiliary cam can be adjusted according to different air suction and exhaust requirements of the engine.

In the embodiment, 8-cylinder diesel engines are taken as an example, 8 intake cams are respectively required to be 8 cylinders, and 8 cylinders are still numbered in the original mode. In a preferred embodiment of the valve camshaft, the intake cams corresponding to the No. 3 cylinder, the No. 4 cylinder, the No. 6 cylinder, and the No. 8 cylinder are provided to have two lift profiles.

As shown in fig. 1, the intake cams corresponding to cylinders No. 1 to 8 are E1, E2, E3, E4, E5, E6, E7, and E8, respectively, and the exhaust cams corresponding to cylinders No. 1 to 8 are a1, a2, A3, a4, a5, A6, a7, and A8, respectively. Fig. 2, 3, 4, and 5 are views showing the structures of the intake cam and the exhaust cam.

The cam of the cam shaft from one end to the other end is respectively an exhaust cam of No. 8 cylinder, an intake cam of No. 4 cylinder, an intake cam of No. 8 cylinder, an exhaust cam of No. 4 cylinder, an exhaust cam of No. 7 cylinder, an intake cam of No. 3 cylinder, an intake cam of No. 7 cylinder, an exhaust cam of No. 3 cylinder, an exhaust cam of No. 6 cylinder, an intake cam of No. 2 cylinder and an exhaust cam of No. 6 cylinder.

The 8 intake cams are respectively E1, E2, E3, E4, E5, E6, E7 and E8, and the 8 exhaust cams are respectively A1, A2, A3, A4, A5, A6, A7 and A8; wherein, the air intake of E1, E2, E5 and E7 is 27.5 degrees before the top dead center, and the air intake is stopped at 38.5 degrees after the bottom dead center; the air intake of the auxiliary cams of E3, E4 and E8 starts to be 10.5 degrees before the bottom dead center, stops to be 67.5 degrees before the top dead center, starts to be 27.5 degrees before the top dead center and stops to be 38.5 degrees after the bottom dead center; e6, the auxiliary cam starts to intake 0.5 degrees before the bottom dead center, stops to intake 57.5 degrees before the top dead center, and the main cam starts to intake 27.5 degrees before the top dead center and stops to intake 38.5 degrees after the bottom dead center; the exhaust cams A1-A8 begin exhaust 57 degrees before bottom dead center and close exhaust 25 degrees after top dead center. Ignition sequence of 8 cylinders of a diesel engine: 1-8-4-5-7-3-6-2.

The top dead center refers to a position where the piston crown is at the maximum distance from the crankshaft center in the diesel engine. I.e. the highest point of the piston stroke, and the position of the piston when the cylinder volume is at a minimum. Bottom dead center refers to the position where the piston crown is at a minimum distance from the crankshaft center in a diesel engine. I.e. the lowest point of the piston stroke, and the position of the piston when the cylinder volume is at its maximum.

The above-mentioned before top dead center means a position not yet reaching the top dead center. The concept of the ignition advance angle is related, the engine needs to be ignited by an angle in advance, otherwise, the ignition is late, and the normal work of the engine is influenced. After bottom dead center is a position where bottom dead center has been passed. Due to the inertia of the air flow, the air continues to be charged into the cylinder, so that the valve is closed after the lower dead point with a delay. The calculation is carried out by taking the upper dead point or the lower dead point as 0 degrees respectively before the upper dead point, before the lower dead point, after the upper dead point and after the lower dead point.

The utility model discloses improved distribution camshaft, distribution camshaft's part admission cam's molded lines change into the structure of two lift molded lines, and remaining part's admission cam's molded lines are unchangeable, and distribution camshaft after the improvement can improve low-speed district cylinder inflation coefficient, improves the air input when the diesel engine low-speed moves to effectively improve diesel engine high temperature low-speed performance, improve diesel engine low-speed moment of torsion.

The utility model discloses the structure sets up rationally, can improve distribution performance, and comprehensive performance is good.

Claims

1. A gas distribution camshaft for improving low-speed performance of a diesel engine is characterized in that four gas inlet cams are provided with two lift type lines, the two lift type lines respectively form a main cam and an auxiliary cam, the phase difference of the vertexes of the two lift type lines is α degrees, and the other four gas inlet cams are single lift type lines.

2. The distribution camshaft for improving the low-speed performance of the diesel engine according to claim 1, characterized in that: the lift of the two lift profiles is 1.038mm and 8.4mm, respectively.

3. The camshaft of claim 2 wherein the two lift profile apexes are out of phase by α degrees of 112.5 degrees.

4. The distribution camshaft for improving the low-speed performance of the diesel engine according to any one of claims 1 to 3, characterized in that: the intake cams corresponding to the No. 3 cylinder, the No. 4 cylinder, the No. 6 cylinder, and the No. 8 cylinder have two lift profiles.

5. The distribution camshaft for improving the low-speed performance of the diesel engine according to claim 4, characterized in that: the cam of the cam shaft from one end to the other end is respectively an exhaust cam of No. 8 cylinder, an intake cam of No. 4 cylinder, an intake cam of No. 8 cylinder, an exhaust cam of No. 4 cylinder, an exhaust cam of No. 7 cylinder, an intake cam of No. 3 cylinder, an intake cam of No. 7 cylinder, an exhaust cam of No. 3 cylinder, an exhaust cam of No. 6 cylinder, an intake cam of No. 2 cylinder, an exhaust cam of No. 5 cylinder, an intake cam of No. 1 cylinder, an intake cam of No. 5 cylinder and an exhaust cam of No. 1 cylinder.