JPH04103234U - Turbocharger rotation speed detection device - Google Patents

Abstract

(57) [Summary] [Purpose] To detect the accurate rotation speed of a turbocharger over the entire rotation range without being affected by electromagnetic noise and with excellent vibration resistance. [Structure] A vibration sensor 26 is attached to the outer surface of the center housing 17, and the detection output from the vibration sensor 26 is passed through an amplifier and a bandpass filter to obtain a peak value of a desired vibration level, and the frequency of this peak value is transmitted to a compressor. By dividing by the number of blades of the fan wheel 14, the rotational speed of the turbine shaft 12 is obtained.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a device for detecting the rotational speed of an automobile turbocharger. be.

0002

[Conventional technology]

In this type of device, a gear is fixed to the turbine shaft, and the gear is placed close to the tooth tips of the gear. An electromagnetic pickup is attached to the housing, and the detection output of this electromagnetic pickup is used to A device that detects the rotational speed of a turbine shaft is known. This device is a tooth tip of a gear. When the position of changes, the inductance of the coil changes, i.e. between the terminals of the coil. Utilizing the characteristic that the voltage of The rotation speed of the bin shaft is calculated.

0003

[Problem that the idea aims to solve]

However, when external electromagnetic noise is applied to the above device, the coil terminals cannot be accurately detected. There was a risk that it would be impossible to count the voltage changes between the two. Also, bad roads for cars etc. or by the rotation of the turbocharger's turbine shaft itself. When vibration occurs at a frequency of , this vibration causes the electromagnetic pickup to resonate There was a problem in which it became impossible to count voltage changes.

0004 The purpose of this invention is to operate a turbocharger without being affected by electromagnetic noise. A turbocharger that can accurately detect rotation speed in the entire rotation range and has excellent vibration resistance. An object of the present invention is to provide a rotation speed detection device.

[0005]

[Means to solve the problem]

The present invention includes a turbine wheel 13 and a compressor at both ends of the turbine shaft 12. The turbine shaft 12 is connected to the center housing 17 via a bearing 16. This is an improvement on the turbocharger installed in the. Its characteristic structure is a vibration sensor attached to the outer surface of the center housing 17. 26, an amplifier 27 for amplifying the detection output of the vibration sensor 26, and an amplifier 27 for amplifying the detection output of the vibration sensor 26. Passes frequencies in the desired band of detection output and removes frequencies in other bands. A bandpass filter 28 is provided.

[0006]

[Effect]

The detection output from the vibration sensor 26 is passed through an amplifier 27 and a bandpass filter 28. contains the peak value of the desired vibration level and converts the frequency of this peak value to the compressor. Accurately obtain the rotational speed of the turbine shaft 12 by dividing by the number of blades of the fan wheel 14. be able to.

[0007]

【Example】

Next, one embodiment of the present invention will be described in detail based on the drawings. As shown in FIG. 1, a turbocharger 11 mounted on an automobile includes a turbine wheel 13 and a compressor fan wheel 14 at both ends of a turbine shaft 12, respectively. The turbine wheel 13 has N ₁ blades 13a, and the compressor fan 14 has N ₂ blades 14a. The turbine shaft 12 is attached to a center housing 17 via a bearing 16, a turbine housing 18 that covers the turbine impeller 13 is attached to one end of the center housing 17, and a compressor fan wheel 14 is attached to the other end of the center housing 17. A compressor housing 19 is attached that covers the. A suction port 18a is provided on the outer peripheral surface of the turbine housing 18, and an exhaust manifold 21 that guides engine exhaust gas to the turbine wheel 13 is connected to the suction port 18a. A discharge port 18b is provided on the surface of the turbine housing 18 opposite to the mounting surface to the center housing 17, and an exhaust pipe 22 is provided at the discharge port 18b to guide the exhaust gas blown onto the turbine impeller 13 to the outside of the vehicle. is connected. A suction port 19a is provided on the surface of the compressor housing 19 opposite to the mounting surface to the center housing 17, and an intake pipe 23 for guiding outside air to the compressor fan wheel 14 is connected to the suction port 19a. A discharge port 19b is provided on the outer circumferential surface of the compressor housing 19, and an intake manifold 24 that guides compressed air to the engine is connected to the discharge port 19b.

[0008] A characteristic configuration of the present invention is that a vibration sensor 26 is attached to the outer surface of the center housing 17. (Fig. 1), and the detection output of the vibration sensor 26 is an amplifier that amplifies the detection output. The output of the amplifier is connected to the input of the vibration sensor 27, and the output of the amplifier is connected to the input of the vibration sensor 26. A bandpass filter that passes frequencies in a desired band and removes frequencies in other bands. It is connected to the input of router 28 (FIG. 2).

The output of bandpass filter 28 is connected to a control input of controller 29 . An engine rotation sensor 31 is provided on the crankshaft of the engine, and its detection output is connected to a control input of the controller 29. A control output of the controller 29 is connected via a drive circuit 32 to an input for adjusting the pass frequency band of the bandpass filter 28 and an input of a linear solenoid 33 (described later) (FIG. 2). Further, as shown in FIG. 3, the controller 29 reads the frequency f at which the vibration level in the frequency band that has passed through the band-pass filter 28 has a prominent peak value P, and uses this frequency f as the frequency f of the blade 14a of the compressor fan 14. The rotational speed R of the turbine shaft 12 is calculated by dividing by the number _N2 . Here, it has been experimentally determined in advance that the peak value P of the vibration level is generated by the rotation of the compressor fan wheel 14. The allowable rotational speed of the turbine shaft 12 is stored in the memory of the controller 29 . A bypass pipe 34 is provided between the suction port 18a and the discharge port 18b of the turbine housing 18, and a wastegate 34a of the bypass pipe 34 is formed into a tapered hole. A linear solenoid 33 in which a shaft 36 is inserted, one end of which faces the waste gate 34a, is attached to the bypass pipe 34, and the linear solenoid 33 is configured to be able to move the shaft 36 in its axial direction by an output signal from the drive circuit 32. . Further, a conical valve 37 capable of sealing the waste gate 34a is fixed to one end of the shaft 36 (FIG. 1).

[0010]The operation of the turbocharger rotation speed detection device configured as described above will be explained. When the engine starts, the controller 29 adjusts the pass frequency band of the bandpass filter 28 based on the detection output of the engine rotation sensor 31, and the detection output of the vibration sensor 26 is passed through the amplifier 27 and the bandpass filter 28 to a desired value. The vibration level of the frequency band is sent to the controller 29. The controller 29 calculates the rotation speed R ₁ of the turbine shaft 12 by dividing the frequency f ₁ of the peak value P ₁ of the vibration level by the number N ₂ of the blades 14a of the compressor fan 14. This rotational speed R ₁ of the turbine shaft 12 can be accurately obtained over the entire rotation range of the turbine shaft 12 without being affected by external electromagnetic noise or vibrations from an automobile or the like.

The controller 29 compares this rotation speed R ₁ with the allowable rotation speed of the turbine shaft 12 , and when the rotation speed R ₁ of the turbine shaft 12 is equal to or higher than the allowable rotation speed, the controller 29 operates the linear solenoid 33 via the drive circuit 32 . do. As a result, the shaft 36 moves in the direction of the solid arrow in FIG. 1, the valve 37 opens, a part of the exhaust gas is guided to the exhaust pipe 22 through the bypass pipe 34, and the rotational speed R ₁ of the turbine shaft 12 increases. The rotation speed becomes below the allowable speed. Therefore, damage to the bearing 16 due to over-rotation of the turbine shaft 12 is prevented, and reliability of the turbocharger 11 is improved. Furthermore, the opening degree of the waste gate 34a can be finely adjusted by the moving distance of the shaft 36, and therefore the flow rate of exhaust gas passing through the bypass pipe 34 can be finely adjusted, so that the rotational speed of the turbine shaft 12 can be smoothly controlled.

0012 In addition, in the embodiment, the controller controls the turbine shaft based on the detection output of the vibration sensor. The rotation speed of the was calculated and the wastegate was configured to open and close, but this is just an example. The conventional mechanical wastegate mechanism, that is, the inside of the intake manifold, When the pressure exceeds a certain level, this pressure resists the elastic force of the spring and separates the waste gate. It may also be used in conjunction with an opening mechanism. In this case, turbocharger reliability is further improved. do.

[0013]

[Effect of the idea]

As described above, according to the present invention, the vibration sensor is mounted on the outer surface of the center housing. installation, connect the detection output of the vibration sensor to the input of the amplifier, and connect the output of the amplifier to the vibration sensor. Passes frequencies in the desired band of the sensor's detection output and passes frequencies in other bands. Since it is connected to the input of the bandpass filter to be removed, the detection output of the vibration sensor is Therefore, the peak value of the desired vibration level can be obtained, and as a result, the frequency of this peak value can be The rotational speed of the turbine shaft can be determined by dividing the number by the number of blades of the compressor fan. can be obtained with high accuracy. In addition, vibration sensors are affected by electromagnetic noise and vibrations from automobiles, etc. Accurate detection is possible over the entire turbocharger rotation range without noise. Additionally, the controller adjusts the waist gauge based on the detected rotational speed of the turbine shaft. Controlling the opening and closing of the gate can improve turbocharger reliability. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a rotational speed detection device for a turbocharger according to an embodiment of the present invention.

FIG. 2 is an electrical circuit diagram of the device.

FIG. 3 is a frequency analysis diagram including peak values of vibration levels detected by the vibration sensor.

[Explanation of symbols]

11 Turbocharger 12 Turbine shaft 13 Turbine wheel 14 Compressor fan wheel 16 Bearing 17 Center housing 26 Vibration sensor 27 Amplifier 28 Bandpass filter

Claims (1)

[Scope of utility model registration request] 1. A turbine wheel (13) and a compressor fan wheel (14) are provided at both ends of a turbine shaft (12), and the turbine shaft (12) is connected to a center housing (17) via a bearing (16). )
a vibration sensor (26) attached to the outer surface of the center housing (17);
and an amplifier (2) that amplifies the detection output of the vibration sensor (26).
7) and a bandpass filter (28) that passes frequencies in a desired band and removes frequencies in other bands among the detection outputs of the vibration sensor (26). Rotation speed detection device.