JPS623111A - Valve timing adjustment device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce gearing noise in a system with a gear between a timing pulley and a cam shaft for the relative turn thereof through shifting in an axial direction, by using a spring for giving no backlash at the gearing portion of the gear with said pulley and cam shaft. CONSTITUTION:The subject device has a constitution wherein a cylindrical gear 3 with helical teeth on the inner periphery thereof is fitted between a timing pulley 1 and a cam shaft 2, and the outer teeth 3a and the inner teeth 3b of said gear 3 are respectively geared with the inner teeth 1a on the inner periphery of the pulley 1 and the outer teeth 2a on the outer periphery of the cam shaft 2. And the gear is moved in an axial direction by a gear drive mechanism 4 and the cam shaft 2 is turned relatively to the pulley 1, thereby changing the operation cycle of a valve. In this case, said gear 3 comprises two gear components 3c and 3d, a thrust pin 3e connecting both components 3c and 3d to each other so as to be axially slidable, and a spring 3b located between said components 3c and 3d and giving a separating force thereto.

Description

[Detailed description of the invention] Industrial application field.

The present invention relates to a pulp timing adjustment device that performs variable control of opening/closing timing of intake and exhaust pulps of an internal combustion engine.

BACKGROUND OF THE INVENTION As shown in FIG. 4, this type of pulp timing adjustment device has a method in which at least one of the teeth provided on the inner and outer peripheries between the timing pulley l and the camshaft 2 is a helical tooth. A certain cylindrical tooth X3 is provided on the outer periphery of the outer tooth 3
Inner #xaK provided around the circumference of ak timing pulley l
The inner teeth ab provided on one circumference are attached to the outer teeth 2a provided on the outer periphery of the camshaft 2 so as to mesh with each other, thereby making it possible to transmit the word of mouth of the tie 2 ring pulley l to the camshaft 2. teeth! 3 in the axial direction of the camshaft 2 by the circular gear drive IEII mechanism 4 using the hydraulic pump 4a and the coil spring 4be.
Suction by the camshaft 2.

It is well known that the exhaust pulp opening/closing timing tFP3 is advanced in accordance with the operating conditions of the fuel engine (for example, US Pat. No. 4,231,330). Note that 5 is a timing belt.

The invention seeks to solve the conventional pulp timing tone above the pulping point! The li device is gear 31
By simply moving the cap of Ericam shaft 2 to the hydraulic pressure, etc., depending on the operating conditions of the internal combustion engine, for example, during high-load operation, the timing of closing the intake pulp can be delayed to reduce the amount of mixed air in town 1a. You can increase the filling efficiency and obtain high output,'! ! 9. During low-load operation, by advancing the timing of closing the intake pulp, the amount of residual burnt gas can be completely reduced, and combustion stability and fuel efficiency can be improved.

However, in this valve timing adjustment device, the gear 3 is located between the timing pulley 1 and the camshaft 2.
Naturally, there is an engagement gap called a pack lattice between these teeth. Therefore, due to the existence of this Patukuratushi,
During operation, the spring force of the pulp spring is applied to the camshaft 20.
If an alternating load is applied in the rotational direction or counter-rotation direction and the rotational torque of the camshaft 20 is caused to fluctuate, meshing noise (hitting noise) is generated. IiI & meeting, even sucking,
Case 4: The timing of opening and closing the exhaust pulp becomes unstable!
- is hot.

Means for Solving the Problems Therefore, in this invention, the tooth X? which connects the tie pulley and the camshaft is used. , a plurality of @X structures provided with outer teeth and inner teeth, a thrust pin that is slidably coupled in the axial direction of the entire camshaft, and the gear structure. It is made up of a coil spring that is interposed between the teeth, and the teeth are spaced apart and the tooth traces are slightly shifted from each other.

Compress the working coil spring, bring the gear components close to each other, and with the tooth traces between the gear components in the next state, the timing pulley is attached to the shaft. When the compressed metal shavings are compressed, the spring force of the coil spring causes the %t#Xm adults to separate, and the tooth traces of each other are slightly shifted, filling the gap.

Therefore, the teeth must be installed on the timing pulley and camshaft with zero backlash, thereby preventing the occurrence of meshing noise caused by the presence of backlash and allowing the pulp timing adjustment device to function properly.

Example Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is an exploded perspective view of both plates 3, which is the gist of the present invention. Both plates 3 cost $11.00 for cutting a long tooth IL. In this embodiment, two T11 wheel structures 3c*3 are formed, and have the same outer teeth 3a and inner teeth 3bg.
d, a thrust pin 3e which is attached to the gear structure 3d of the gear structure 3d, and the thrust pin 3e which is slidably coupled in the axial direction of the camshaft 2;
# Interposed between 3d “n and these teeth I
Construct 3 c * 3 (! k 111 intervals □
``Coils whose tooth traces are slightly shifted from each other.
- Consists of spring 3f. 3g&'! :f
Nine gear structure 3C13 to which the spring 3f is attached
-rL7't spring receiving hole provided on one side of d, 3h
is attached to the tip of thrust pin 3e.
It is 'ng.'

The coil spring 3f cooperates with the thrust pin 3e to couple the plate components Bcs3d to each other so that they can move slightly in the rotational and axial directions with the spring force t of the coil spring 3f itself. . Here, this l! Ii
! The mutual rotational and axial movement of the constituent bodies 3cm3a increases the apparent thickness of the nine teeth formed on the circumference and outer periphery of the inner gear a of the timing pulley l and the camshaft 2. $31 for each outer tooth 2a of
This makes it possible to set the number of batches of 3 to zero, making it possible to assemble 9 sets.

In other words, since at least one of the teeth (double-edged in this example) formed on the inner and outer circumferences is a bevel, the width of the 1-hole structure 3 C63d, which has been cut and divided as described above, is wider than the cutting width. By connecting them with the same dimensions, the mutual tooth traces will be slightly shifted, and the companion gear structure 3 will be connected.
The apparent tooth thickness caused by c and 3d will increase.

Therefore, by connecting and configuring it like this, 2 @ x a vr
Pull the timing pulley l to approximately the same size as the cutting width.
and the outer teeth 2a of the camshaft 2, respectively. This flK work is #1 plate structure 3
The third part of c * 3 d is coil spring 3f.
With the axial spring force generated by itself, the inner gear a of the timing pulley l and the outer gear 112a of the camshaft 2 are moved in a direction that makes the looseness zero. 3 timing pulley
And, nine assemblies are completed with zero backlash for the camshaft 2. This is the spring force given by the coil spring 3f.
' has not been exhausted, and the assembled state with zero backlash continues thereafter. Incidentally, since at least one of the teeth formed on the outer circumference of both discs 3 is a helical tooth, each gear component 3c, 3d is a coil spring 3f.
In the closing state, these IV1s exert a wedge action on the timing pulley l and the teeth of the camshaft 2.

While the camshaft 2 is in a meshing state, the camshaft 2 is rotationally driven without burdening the coil spring 3f with torque transmission.

In FIG. 3, the tooth JL3j is mounted between the timing pulley l and the camshaft 2 in nine states so as to be slidable in the axial direction of the camshaft 2 as described above. The teeth Ks are then driven by a gear drive mechanism 4. This tooth] l[Driver 11IJ mechanism 4 is a hydraulic pump 4a that hydraulically supplies oil pressure to one end side of the gear 3 via a pressure receiving piston 4cg! 3 and a return spring 4b attached to the other side of the camshaft 2. During high-load operation, the hydraulic passage 4 (
Hydraulic pressure is supplied to one end side of gear 3 through n% 1', and when storm 3 moves to the left in Figure 3 while compressing return spring 4b, timing pulley 1
□ On the other hand, the camshaft 2 moves simultaneously in one direction to delay the tying that closes the intake pulp, thereby increasing the filling efficiency vi-.

During low-load operation, when the hydraulic pump 4a stops supplying hydraulic pressure 1Ifj to one end of the teeth IL3, the gear 3 moves to the left in FIG. By advancing the closing timing and reducing the amount of residual burnt gas, combustion stability is improved.

The same goes for fuel efficiency.

In addition, in the embodiment shown in the drawings, the rC gear drive mechanism 4
.

It is also possible to use a step motor or the like instead of the hydraulic pump to move the upper camshaft 20 in the axial direction.
,.

Effects of the Invention As explained above, the present invention has teeth that connect the timing pulley l and the camshaft 2! 3t1 thrust pin 3
A coil spring 3f'ffi is interposed between the gears 3c and 3d. The apparent thickness of the teeth formed on the circumference and outer periphery of the component 3Cs3d is adjusted to make the teeth] 1g @ for each of the inch gear a of the timing pulley l and the outer 1l12a of the camshaft 2. It can be assembled with zero backlash. Therefore, it is possible to completely prevent the occurrence of chewing noise caused by the presence of bumps, and to stabilize the timing of opening and closing the suction and exhaust pulps. Furthermore, even if the finish of the gear 3, the inner gear a of the timing pulley l that meshes with the gear 3, and the outer teeth 2a of the camshaft 2 are lowered to 11 degrees,
Although irregularities do not occur in meshing, the function of the pulp timing adjustment device is not deteriorated, so manufacturing is facilitated and manufacturing costs are reduced.
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[Brief explanation of the drawing]

Figure $1 shows the pulp timing adjustment device of the present invention.
"To use tRjL +Z) @ A perspective view of the breath component in good condition after being disassembled. Figure 2 is a partially fragmented sectional view of the assembled state. Figure 3 is a pulp timing UNI showing an embodiment of the present invention.
□Cross-sectional view of the device, FIG. 4 is a cross-sectional view of a conventional pulp timing adjustment device. l...timing pulley, 1a...inner tooth, 2.
...Camshaft, 2a...Outer tooth, 3...1l
Ji, 3a...outer tooth, 3b...inner tooth s
3 c # 3d... Tooth storm component %313... Thrust pin, 3f... Coil spring. Two other people Figure 1 Figure 2 Figure 3 Figure 3 --- One meeting Figure 4

Claims (1)

[Claims] (1) A cylindrical gear (3) in which at least one of the teeth provided on the outer periphery of the circle between the timing pulley (1) and the camshaft (2) is helical. The outer tooth (3a) provided on the outer periphery is connected to the timing pulley (1).
The inner teeth (1a) provided on the inner periphery of the camshaft (2) mesh with the outer teeth (2a) provided on the outer periphery of the camshaft (2). By making it possible to transmit the rotation of 1) to the camshaft (2) and moving the gear (3) in the axial direction of the camshaft (2) with a gear drive mechanism (4),
The camshaft (2) is connected to the timing pulley (1).
) is rotated relative to the camshaft (2).
In a valve timing adjustment device for an internal combustion engine that can change the timing of opening and closing of an exhaust valve, the gear (3) includes a plurality of gear structures (3c) each having an outer tooth (3a) and an inner tooth (3b); (3d), and a thrust pin (3e) slidably connecting these gear components (3c) and (3d) in the axial direction of the camshaft (2);
A coil spring (3f) that is interposed between the gear components (3c) and (3d) and that separates the gear components (3c) and (3d) so that their mutual tooth traces are slightly shifted. A valve timing adjustment device for an internal combustion engine, comprising: