JP2023104167A - balancer device - Google Patents

Abstract

To provide a balancer device capable of suppressing rolling vibration in driving an engine at relatively low rotation and high load at least.SOLUTION: A balancer device 100 includes a crankshaft 10, a normal rotation balancer shaft 110 which is the only rotation shaft rotating with rotation of the crankshaft 10 and which rotates in a direction same with a rotation direction of the crankshaft 10 at a rotation speed twice as a rotation speed of the crankshaft 10, and a balancer weight 112 fixed to the normal rotation balancer shaft 110.SELECTED DRAWING: Figure 1

Description

This disclosure relates to a balancer device.

2. Description of the Related Art Conventionally, there is known a balancer device for reducing vibration or noise caused by driving an engine. For example, Japanese Unexamined Patent Application Publication No. 2007-46633 discloses a balancer device including a crankshaft, a piston connected to the crankshaft, two balancer shafts, and a balance weight fixed to each balancer shaft. ing. Each balancer shaft rotates in opposite directions to each other at a rotational speed twice that of the crankshaft.

JP-A-2007-46633

In a four-cylinder engine, the roll moment caused by the combustion pressure in the cylinder and the roll moment caused by the inertial force of the piston system act in opposite directions. It is known that the roll moment caused by the combustion pressure in the cylinder has a large effect at high load, and the roll moment caused by the inertial force of the piston system has a large effect at high rotation. Diesel engines for passenger cars are usually balanced between 2000 rpm and 4000 rpm and often have a minimum value.

For example, the engine of a hybrid vehicle tends to be operated under low rotation and high load conditions, unlike in the past. Under such conditions, the roll moment caused by the combustion pressure in the cylinder becomes dominant, so it is desired to reduce the rolling vibration, especially when the engine is driven at low speed and high load. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a balancer device capable of suppressing rolling vibration at least when an engine is driven at relatively low speed and high load.

A balancer device according to a first aspect of this disclosure comprises a crankshaft and a sole rotating shaft that rotates with the rotation of the crankshaft, wherein the rotational speed of the crankshaft is adjusted in the same direction as the direction of rotation of the crankshaft. and a balancer weight fixed to the positive rotation balancer shaft.

A balancer device according to a second aspect of the present disclosure includes a crankshaft, a positive rotation balancer shaft that rotates in the same direction as the rotation direction of the crankshaft at twice the rotation speed of the crankshaft, and A counter-rotating balancer shaft that rotates in a direction opposite to the rotational direction of the crankshaft at a rotational speed twice the rotational speed of the crankshaft, a forward-rotating balancer weight fixed to the forward-rotating balancer shaft, and the reverse-rotating balancer. a reverse rotation balancer weight fixed to a shaft, wherein the weight of the forward rotation balancer weight is larger than the weight of the reverse rotation balancer weight.

A balancer device according to a third aspect of the present disclosure includes a crankshaft, a positive rotation balancer shaft that rotates in the same direction as the rotation direction of the crankshaft at twice the rotation speed of the crankshaft, and A counter-rotating balancer shaft that rotates in a direction opposite to the rotational direction of the crankshaft at a rotational speed twice the rotational speed of the crankshaft, a forward-rotating balancer weight fixed to the forward-rotating balancer shaft, and the reverse-rotating balancer. A two-shaft state in which both the counter-rotating balancer weight fixed to the shaft, the forward-rotating balancer shaft and the counter-rotating balancer shaft rotate together with the crankshaft, and only the forward-rotating balancer shaft rotates together with the crankshaft. and a switching mechanism capable of switching to and from the 1-axis state.

According to this disclosure, it is possible to provide a balancer device capable of suppressing rolling vibration at least when the engine is driven at relatively low speed and high load.

1 is a diagram schematically showing an engine including a balancer device according to a first embodiment of the present disclosure; FIG. 2 is an enlarged perspective view of a portion of the engine shown in FIG. 1; FIG. FIG. 5 is a diagram schematically showing part of a balancer device according to a second embodiment of the present disclosure; 4 is a diagram schematically showing a uniaxial state in the balancer device shown in FIG. 3; FIG. 4 is a graph showing the relationship between engine speed and torque; 4 is a table showing configurations of examples and comparative examples. 4 is a graph showing the relationship between engine speed and vibration level.

An embodiment of the invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are given the same numbers.

(First embodiment)
FIG. 1 is a plan view schematically showing an engine according to a first embodiment of the invention. FIG. 2 is an enlarged perspective view of a portion of the engine shown in FIG. 1; FIG.

As shown in FIGS. 1 and 2, the engine 1 includes a crankshaft 10, a connecting rod 20, a piston 30, a cylinder (not shown), and a balancer device 100. The engine 1 of this embodiment is of a four-cylinder type.

Piston 30 is connected to crankshaft 10 via connecting rod 20 . The piston 30 reciprocates within the cylinder. The reciprocating movement of the piston 30 is transmitted to the crankshaft 10 via the connecting rod 20, thereby rotating the crankshaft 10. As shown in FIG.

The balancer device 100 has at least the function of reducing the roll moment caused by the combustion pressure in the cylinder. The balancer device 100 is connected to a forward rotation balancer shaft 110, a forward rotation side balancer weight 112, a forward rotation side gear 114, a reverse rotation balancer shaft 120, a reverse rotation side balancer weight 122, and a reverse rotation side gear 124. A member 130 and a housing 140 are provided.

Forward rotation balancer shaft 110 rotates integrally with crankshaft 10 . As shown in FIGS. 1 and 2, forward rotation balancer shaft 110 is connected to crankshaft 10 by a connecting member 130 such as a chain so as to rotate in the same direction as crankshaft 10 rotates. The positive rotation balancer shaft 110 rotates in the same direction as the rotation of the crankshaft 10 at a rotational speed twice as high as the rotational speed of the crankshaft 10 . The positive rotation balancer shaft 110 is arranged below the crankshaft 10 .

The forward rotation balancer weight 112 is fixed to the forward rotation balancer shaft 110 . In this embodiment, two forward rotation balancer weights 112 are fixed to the forward rotation balancer shaft 110 .

The forward rotation side gear 114 is fixed to the forward rotation balancer shaft 110 .

The reverse rotation balancer shaft 120 is arranged below the crankshaft 10 in a posture parallel to the forward rotation balancer shaft 110 . The counter-rotating balancer shaft 120 rotates in a direction opposite to the rotational direction of the crankshaft 10 at a rotational speed twice as high as the rotational speed of the crankshaft 10 .

The reverse rotation side balancer weight 122 is fixed to the reverse rotation balancer shaft 120 . In this embodiment, two reverse rotation side balancer weights 122 are fixed to the reverse rotation balancer shaft 120 . The weight of each reverse rotation side balancer weight 122 is smaller than the weight of each forward rotation side balancer weight 112 . In other words, the weight of each forward rotation side balancer weight 112 is greater than the weight of each reverse rotation side balancer weight 122 .

The reverse rotation side gear 124 is fixed to a portion of the reverse rotation balancer shaft 120 that faces the forward rotation side gear 114 . The reverse rotation side gear 124 meshes with the forward rotation side gear 114 . Therefore, the reverse rotation balancer shaft 120 rotates in a direction opposite to the rotation direction of the forward rotation balancer shaft 110 .

Housing 140 supports forward rotation balancer shaft 110 and reverse rotation balancer shaft 120 via bearings 142 . The housing 140 accommodates the forward rotation balancer shaft 110 , the forward rotation side balancer weight 112 , the forward rotation side gear 114 , the reverse rotation balancer shaft 120 , the reverse rotation side balancer weight 122 and the reverse rotation side gear 124 .

As described above, in the balancer device 100 of the present embodiment, the weight of the forward rotation side balancer weight 112 is larger than the weight of the reverse rotation side balancer weight 122, so that the engine 1 is driven at relatively low speed and high load. Rolling vibration and noise resulting therefrom are reduced.

In addition, in the first embodiment, the reverse rotation balancer shaft 120, the reverse rotation side balancer weight 122, and the reverse rotation side gear 124 may be omitted.

(Second embodiment)
Next, a balancer device 100 according to a second embodiment of the present invention will be described with reference to FIGS. 3 to 5. FIG. In addition, in the second embodiment, only parts different from the first embodiment will be described, and descriptions of the same structures, functions and effects as those of the first embodiment will not be repeated.

In this embodiment, the balancer device 100 further includes a switching mechanism 150 and a control section 160 .

As shown in FIG. 3 , in this embodiment, the reverse rotation side gear 124 is rotatable relative to the reverse rotation balancer shaft 120 .

The switching mechanism 150 switches between the 2-axis state and the 1-axis state. The two-shaft state is a state in which both the forward rotation balancer shaft 110 and the reverse rotation balancer shaft 120 rotate together with the crankshaft 10 . The 1-shaft state is a state in which only the forward rotation balancer shaft 110 rotates together with the crankshaft 10 . The switching mechanism 150 has a rotor 152 , a stator 154 , a coil 156 and an armature 158 .

Rotor 152 is fixed to counter-rotating balancer shaft 120 so as to rotate integrally with counter-rotating balancer shaft 120 .

The stator 154 is fixed via a bearing 155 to a portion of the counter-rotating balancer shaft 120 that faces the rotor 152 in the axial direction of the counter-rotating balancer shaft 120 .

A coil 156 is attached to the stator 154 .

The armature 158 is fixed to the reverse rotation side gear 124 so as to rotate together with the reverse rotation side gear 124 . Armature 158 engages rotor 152 as shown in FIG. 3 when coil 156 is energized. As a result, the rotor 152 rotates together with the reverse rotation side gear 124 . In this state, the reverse rotation balancer shaft 120 and the reverse rotation side balancer weight 122 rotate together with the forward rotation balancer shaft 110 and the forward rotation side balancer weight 112 via the reverse rotation side gear 124 and the forward rotation side gear 114 . That is, the state in which current is supplied to the coil 156 corresponds to the biaxial state.

On the other hand, the armature 158 is separated from the rotor 152 as shown in FIG. 4 when the coil 156 is de-energized. In this state, the reverse rotation balancer shaft 120 and the reverse rotation side balancer weight 122 are not rotating, and only the forward rotation balancer shaft 110 and the forward rotation side balancer weight 112 are rotating together with the crankshaft 10 . That is, the state in which the coil 156 is de-energized corresponds to the uniaxial state. In the 1-axis state, the reverse rotation side gear 124 and the armature 158 rotate relative to the reverse rotation balancer shaft 120 .

The controller 160 controls the switching mechanism 150 . Specifically, control unit 160 controls whether or not current is supplied to coil 156 based on a map showing the relationship between engine speed and engine torque. The control unit 160 has a storage unit 162 and a switching unit 164 .

The storage unit 162 stores a map showing the relationship between the engine speed and the engine torque, as shown in FIG. This map is acquired in advance and stored in the storage unit 162 . The map includes a single-axis region R1 in which only the forward rotation balancer shaft 110 rotates, and a two-axis region R1 in which both the forward rotation balancer shaft 110 and the reverse rotation balancer shaft 120 rotate. A region R2 is defined. In addition, in FIG. 5, the uniaxial region R1 is hatched.

The switching unit 164 outputs a signal to supply current to the coil 156 when the engine speed and torque are within the range of the two-axis region R2, and the engine speed and torque are within the range of the one-axis region R1. , a signal for stopping the current supply to the coil 156 is output. Note that the rotation speed and torque of the engine are obtained from various sensors.

Here, an example of the timing for switching from the 1-axis state to the 2-axis state, that is, the timing at which the switching unit 164 outputs a signal that supplies current to the coil 156 will be described. In the one-shaft state, the reverse rotation side balancer weight 122 is positioned below the reverse rotation balancer shaft 120 due to its own weight.

In this 1-axis state, when the engine speed and torque enter the 2-axis region R2 in the map stored in the storage unit 162, the switching unit 164, for example, switches the forward rotation balancer weight 112 to the forward rotation balancer shaft. When positioned below 110 , it outputs a signal that supplies current to coil 156 . The position of the positive rotation side balancer weight 112 is detected by a sensor together with the phase of the crankshaft 10, for example.

In the balancer device 100 according to the second embodiment described above, when the engine 1 is driven at relatively low speed and high load, the switching mechanism 150 is set to the 1-shaft state (the reverse rotation balancer shaft 120 is stopped). When the engine 1 is driven at a relatively high rotation speed, the switching mechanism 150 is set to the two-shaft state (the state in which the reverse rotation balancer shaft 120 rotates together with the forward rotation balancer shaft 110), whereby the rotation speed is relatively low. In addition, it is possible to reduce rolling vibration and noise caused by the rolling vibration in a range from a state in which the engine 1 is driven at a high load to a state in which the engine 1 is driven at a relatively high speed.

Incidentally, in the second embodiment, the weight of the reverse rotation side balancer weight 122 may be set equal to or larger than the weight of the forward rotation side balancer weight 112 .

Next, examples of the balancer device 100 according to the first and second embodiments will be described with reference to FIGS. 6 and 7 together with comparative examples.

As shown in FIG. 6, Example 1 is an example of the first embodiment, and Example 2 is a modified example of the first embodiment (reverse rotation balancer shaft 120, reverse rotation side balancer weight 122, and reverse rotation balancer weight 122). Example 3 is an example in which the rotation-side gear 124 is omitted), and Example 3 is an example of a two-shaft state in the second embodiment. The comparative example does not have the forward rotation balancer shaft 110 and the forward rotation side balancer weight 112 , but has only the reverse rotation balancer shaft 120 and the reverse rotation side balancer weight 122 .

As shown in FIG. 7, in Examples 1 and 2, it was confirmed that the vibration level was reduced when the engine 1 was driven at a relatively low speed. It was confirmed that the vibration level was reduced while the engine 1 was being driven. On the other hand, in the comparative example, it was confirmed that the vibration level was not reduced in the entire range from the state in which the engine 1 was driven at relatively low speed to the state in which it was driven at relatively high speed. It should be noted that the switching mechanism 150 in the third embodiment corresponds to the first embodiment.

[Aspect]
It will be appreciated by those skilled in the art that the exemplary embodiments and examples described above are specific examples of the following aspects.

A balancer device according to a first aspect of this disclosure comprises a crankshaft and a sole rotating shaft that rotates with the rotation of the crankshaft, wherein the rotational speed of the crankshaft is adjusted in the same direction as the direction of rotation of the crankshaft. and a balancer weight fixed to the positive rotation balancer shaft.

In this balancer device, the balance weight rotates around the forward-rotating balancer shaft, thereby reducing rolling vibration and noise resulting therefrom when the engine is driven at relatively low speed and high load.

A balancer device according to a second aspect of the present disclosure includes a crankshaft and a positive rotation balancer shaft that rotates in the same direction as the crankshaft at a rotational speed twice as high as that of the crankshaft. , a reverse rotation balancer shaft rotating in a direction opposite to the rotation direction of the crankshaft at a rotational speed twice the rotational speed of the crankshaft; a forward rotation side balancer weight fixed to the forward rotation balancer shaft; and a reverse rotation balancer weight fixed to the rotation balancer shaft, wherein the weight of the forward rotation balancer weight is larger than the weight of the reverse rotation balancer weight.

In this balancer device, the weight of the balancer weight on the forward rotation side is larger than the weight of the balancer weight on the reverse rotation side, so rolling vibration and noise caused by the rolling vibration when the engine is driven at relatively low speed and high load are reduced. be.

A balancer device according to a third aspect of the present disclosure includes a crankshaft and a positive rotation balancer shaft that rotates in the same direction as the rotation direction of the crankshaft at twice the rotation speed of the crankshaft. , a reverse rotation balancer shaft rotating in a direction opposite to the rotation direction of the crankshaft at a rotational speed twice the rotational speed of the crankshaft; a forward rotation side balancer weight fixed to the forward rotation balancer shaft; A two-axis state in which both the forward-rotating balancer shaft and the reverse-rotating balancer shaft rotate together with the crankshaft, and only the forward-rotating balancer shaft rotates together with the crankshaft. A rotating uniaxial state and a switching mechanism capable of switching between the two states are provided.

In this balancer device, when the engine is driven at relatively low speed and high load, the switching mechanism is set to the 1-shaft state, and when the engine is driven at relatively high speed, the switching mechanism is set to the 2-shaft state. By doing so, it is possible to reduce the rolling vibration and the noise caused by the rolling vibration in the range from the state where the engine is driven at relatively low speed and high load to the state where the engine is driven at relatively high speed. .

The balancer device may further include a control section that controls the switching mechanism. The control unit may switch between the 2-axis state and the 1-axis state based on a map showing the relationship between engine speed and torque.

It should be noted that the embodiments and examples disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments and examples, and includes all modifications within the meaning and scope equivalent to the scope of the claims.

1 engine, 10 crankshaft, 20 connecting rod, 30 piston, 100 balancer device, 110 forward rotation balancer shaft, 112 forward rotation side balancer weight, 114 forward rotation side gear, 120 reverse rotation balancer shaft, 122 reverse rotation side balancer weight, 124 Reverse rotation side gear 130 Connection member 140 Housing 150 Switching mechanism 152 Rotor 154 Stator 156 Coil 158 Armature 160 Control unit.

Claims (4)

a crankshaft and
a positive rotation balancer shaft, which is the only rotating shaft that rotates together with the rotation of the crankshaft, and rotates in the same direction as the rotation direction of the crankshaft at a rotation speed twice as high as that of the crankshaft;
a balancer weight fixed to the positive rotation balancer shaft. a crankshaft and
a positive rotation balancer shaft that rotates in the same direction as the rotation direction of the crankshaft at a rotation speed twice as high as the rotation speed of the crankshaft;
a counter-rotating balancer shaft that rotates in a direction opposite to the rotational direction of the crankshaft at a rotational speed twice as high as the rotational speed of the crankshaft;
a positive rotation side balancer weight fixed to the positive rotation balancer shaft;
a counter-rotating balancer weight fixed to the counter-rotating balancer shaft,
The balancer device, wherein the weight of the forward rotation side balancer weight is larger than the weight of the reverse rotation side balancer weight. a crankshaft and
a positive rotation balancer shaft that rotates in the same direction as the rotation direction of the crankshaft at a rotation speed twice as high as the rotation speed of the crankshaft;
a counter-rotating balancer shaft that rotates in a direction opposite to the rotational direction of the crankshaft at a rotational speed twice as high as the rotational speed of the crankshaft;
a positive rotation side balancer weight fixed to the positive rotation balancer shaft;
a counter-rotating balancer weight fixed to the counter-rotating balancer shaft;
a switching mechanism capable of switching between a 2-axis state in which both the forward rotation balancer shaft and the reverse rotation balancer shaft rotate together with the crankshaft, and a 1-axis state in which only the forward rotation balancer shaft rotates together with the crankshaft; A balancer device, comprising: further comprising a control unit that controls the switching mechanism,
4. The balancer device according to claim 3, wherein the control unit switches between the two-axis state and the one-axis state based on a map showing the relationship between engine speed and torque.

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