JP2013126506A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in which when an endoscope apparatus is performed such that the bending part inside an insertion part is subjected to bend operation by a small motor, desired bending operation is not obtained by the shortage of a driving force.SOLUTION: The endoscope apparatus comprises as follows. The threshold that associates the curve amount of a bend part, a caused load, and the driving force of a drive part is set, when any one of the curve amount, the load, and the driving force reaches the threshold with bending operation, a driving power source by serial current energized to a motor is switched to a pulse power source by pulse current, wherein the pulse power source has a peak value exceeding the maximum serial current that can be driven in the range of maximum allowable temperature or lower and whose cycle includes non-application time for which the drive part is maintained in maximum allowable temperature or lower.

Description

  The present invention relates to an endoscope apparatus in which a small motor is mounted on an endoscope body and a bending portion is bent to a desired state.

  In a general endoscope apparatus, when the insertion portion of the endoscope main body is inserted into a bent tube hole, the observer rotates the angle knob of the operation portion by manual operation to A desired image is observed by bending a curved portion provided on the distal end side. In addition, an endoscope apparatus has been proposed in which a motor is mounted in the operation section of the endoscope body, and a bending switch is bent by electric drive by operating a remote control switch or the like instead of the angle knob, and performing observation. .

  Furthermore, for example, Patent Document 1 includes two bending portions arranged so as to be continuous with the insertion portion, one bending portion is bent by manual operation, and the other bending portion is bent by electric operation by a motor. Endoscopes have been proposed. In addition, Patent Document 2 discloses an endoscope in which a first bending portion and a second bending portion are provided, and both are driven while the bending angle is controlled by a motor.

JP-A-6-217929 JP 2010-000201 A JP 2002-315720 A

  In the above-described endoscope apparatus in which the bending portion is driven by a motor, it is desired that the operation portion does not become so large and the weight does not increase as compared with the manual type. For this reason, it is desirable that the motor and its drive mechanism be miniaturized. Generally, when a motor is downsized, output performance (torque output or the like) is lowered. For this reason, it is feared that the desired bending operation of the bending portion cannot be performed, and depending on the performance of the motor itself by normal use, a sufficient size reduction cannot be realized.

  In general, a motor has a proportional relationship between a consumed current value and an output torque value. When the required torque value is close to the upper limit in terms of performance for a small motor, the maximum current flows through the motor coil as compared with the steady state, so that the motor body becomes hot due to heat loss. Further, when trying to obtain torque, it leads to damage (burnout) to the coil wire, which is not preferable. Patent Document 3 discloses an endoscope apparatus that uses a pulsed drive voltage in order to prevent a wire provided in an insertion portion that performs a bending operation of the bending portion from breaking due to a sudden overload. Proposed.

  Accordingly, an object of the present invention is to provide an endoscope apparatus that can perform a bending operation of a bending portion by a small motor.

To solve the above problem,
In order to achieve the above object, an embodiment according to the present invention has a bending portion disposed on the distal end side where an observation optical system is provided, an insertion portion that can be inserted into a tube hole, and the bending portion at a desired bending angle. In accordance with an instruction from the bending instruction input unit, a bending instruction input unit that instructs the bending unit to have a bending amount that suggests a desired bending angle by the bending driving mechanism, The bending operation is performed at a threshold value that is set by associating a driving unit that generates a driving force for bending the mechanism, a load that acts on the bending unit caused by the bending amount, and a driving force that is generated by the driving unit. When any of the obtained bending amount, the load, and the driving force reaches, the driving power source by the continuous current energized to the motor can be driven within the range of the maximum allowable temperature in the driving unit. Switching to a pulsed power supply with a pulsed current that has a peak value that exceeds a large continuous current and the drive unit is maintained at a temperature below the maximum allowable temperature and includes a non-application time in the cycle, and drives the motor by energizing it. And a control unit.

  ADVANTAGE OF THE INVENTION According to this invention, the endoscope apparatus which can bend | curve a bending part with a small motor can be provided.

FIG. 1 is a block diagram showing a conceptual configuration of an endoscope system equipped with a motor according to the present invention. FIG. 2 is a diagram illustrating an example of a pulse current applied to the motor under the maximum allowable temperature and an application time. FIG. 3 is a diagram for explaining a cycle according to an on time and an off time of a pulse current energized to the motor. FIG. 4 is a diagram illustrating a conceptual configuration of an endoscope system including the motor according to the first embodiment. FIG. 5 is a diagram schematically illustrating the configuration of the first bending portion, the second bending portion, and the operation portion in the insertion portion of the endoscope according to the first embodiment. FIG. 6 is a flowchart for explaining the first drive control of the second bending portion in the first embodiment. FIG. 7 is a flowchart for explaining the second drive control of the second bending portion in the first embodiment. FIG. 8 is a diagram schematically illustrating the configuration of the first bending portion, the second bending portion, and the operation portion in the insertion portion of the endoscope according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a configuration example of an endoscope system driven by a small motor of the present invention.

  The endoscope system 1 is roughly divided into an endoscope main body 2 on which a small motor described later is mounted, a light source 3 that gives illumination light to the endoscope main body 2, and an image signal captured by the endoscope main body 2. A video processor 4 that generates a standard video signal by processing, and a monitor 5 that displays a color observation image (endoscopic image) based on the video signal.

  The endoscope main body 2 and the light source 3 are detachably connected by a connector 6 with a universal cord 7 containing an image / control signal cable, a drive power cable, a light guide for transmitting illumination light from the light source 3 and the like. Yes.

  The video processor 4 can be connected to an image recording device (not shown). Instead of the light source 3 separate from the endoscope body 2, a small light source such as an LED may be provided in the endoscope body 2 as a part of the illumination optical system.

  The endoscope main body 2 includes an operation unit (endoscope main body) 8 and an insertion unit 9. The operation section (endoscope body) 8 is operated by the operator to perform a bending operation on the bending section 14. The insertion unit 9 has an elongated shape, extends from the operation unit 8, is inserted into a tube hole (not shown), and observes a subject (observation target site) in the tube hole. The universal cord 7 is connected to the observation optical system connector 15 provided on the side surface of the operation unit 8.

  The insertion portion 9 includes a distal end hard portion 16 provided at the distal end thereof, a bending portion 14 provided on the rear end side of the distal end hard portion 16, which can be bent by operation of the operation portion 8, and a rear end of the bending portion 14. And a long and flexible tubular portion 17 provided on the side and formed by a soft and tubular member. That is, the insertion portion 9 includes a distal end hard portion 16, a bending portion 14, and a tubular portion 17 that are integrally formed continuously from the distal end side toward the proximal end side.

  The distal end hard portion 16 includes an image pickup portion 18 and a light guide 19. The imaging unit 18 incorporates an imaging lens system for forming a subject image and a circuit board for driving a solid-state imaging device (not shown) such as a CCD or CMOS as an observation optical system. The light guide 19 propagates illumination light from the light source 3 for illuminating the observation target site in the body cavity as an illumination optical system. As a result, the subject is irradiated with illumination light from the distal end surface of the distal end hard portion 16, the illuminated subject is imaged by the imaging unit 18, image processing is performed by the video processor 4, and an image of the subject is displayed on the monitor 5.

  The bending portion 14 includes a bending tube 14a formed of a plurality of known bending pieces, a blade disposed outside the bending tube 14a, and a skin disposed outside the blade. For example, four (only two are shown) angle wires 22 (U 'and D' are shown) are fixed to the tip of the bending tube 14a of the bending portion 14 in correspondence with each bending direction. The bending portion 14 is bent by the angle wires pulled by the motor 26. That is, with these angle wires, the bending portion 14 is set as the first and second directions in the up / down (UP / DOWN) direction (indicated by U ′ and D ′) and the third and fourth directions as the left and right (RIGHT / LEFT) directions. Can be curved.

  As shown in FIG. 1, the base end side of the angle wire 22 is wound around and fixed to a drum 25 inside the operation unit 8. In this example, one motor and two wires are shown in order to simplify the drawing and make the description easy to understand.

  The drum 25 is provided with a motor 26 and an encoder (rotation position detection unit) 27 that detects a rotation amount (rotation angle) ω of the motor 26. In the present embodiment, the motor 26 is assumed to be a DC motor driven by a DC power supply (pulse power supply), but is not limited to this. The rotation amount of the bending drive mechanism is detected from the rotation amount ω of the motor 26 detected by the encoder 27. The motor 26 is a driving unit that generates a driving force for bending the bending unit 14.

  The bending tube 14a, the wire 22, the drum 25, and the motor 26 form a bending drive mechanism that bends the bending portion 14. Here, the position where the bending portion 14 is straight is defined as the initial position (neutral position) of the motor 26. In FIGS. 1 and 2, the motor 26 and the encoder 27 are housed in the operation unit 8 and an operation switch (not shown) is exposed to the outside, but is not particularly limited. 26 may be disposed inside the insertion portion 9 side.

Next, a drive circuit in the motor 26 will be described with reference to FIG.
The motor drive circuit 31 disposed in the operation unit 8 includes a control unit 32, a motor power supply unit 33, and a potentiometer 34. An operation switch 30 that is a bending instruction input unit is provided on the exterior surface of the operation unit 8. Further, the operation switch 30 may be a separate remote control switch as long as the endoscope main body is mounted on an operation arm or the like. Further, the motor drive circuit 31 can be disposed in the video processor 4 in order to reduce the size and weight of the operation unit 8.

  The control unit 32 is mainly composed of a control microcomputer (hereinafter referred to as a CPU or an arithmetic processing unit). Specifically, the CPU 41 that controls and calculates each part, the resistance value measuring unit 42 that measures the resistance value of the potentiometer 34, the count processing unit 43 that counts the pulses of the encoder 27, and the torque generated by the motor 26 A torque calculation unit (torque amount detection unit) 44 that calculates T, a threshold value input unit (setting unit) 45, and a storage unit 46 are configured.

  The motor power supply unit 33 is a drive that energizes the motor 26 (or flows to the motor 26) in addition to a power supply circuit (not shown) that generates a power supply (DC power supply and pulse power supply) for driving the motor 26. A current measuring unit 47 that measures the current I and a voltage setting unit 48 that sets a voltage (or duty ratio) to be applied to the motor 26 are included.

  The resistance value measuring unit 42 measures the resistance value of the potentiometer 34 synchronized with the drum 25. With this resistance value, an operation amount in the UD direction by the drum 25, that is, an input amount (rotation angle) ψ can be obtained, and the bending amount of the bending portion 14 in the UD direction is estimated. The threshold input unit (threshold setting unit) 45 is used to set a threshold angle for causing the bending unit 14 to perform a bending operation. The storage unit 46 stores a threshold angle, an operation amount (rotation angle of the bending portion) ψ in the UD direction of the operation switch 30, rotation position information (rotation angle) ω of the motor 26, and the like. The count processing unit 43 obtains rotational position information (rotation angle) ω of the motor 26 from the count number of encoder pulses output from the encoder 27.

[Motor drive method]
Next, drive control in the motor 26 of the present embodiment will be described. FIG. 2 is a characteristic diagram of the motor 26 of the present embodiment.
In general, the relationship between the drive current I flowing to the motor 26, driving force by the motor 26 is output (torque) T is expressed as T = _{k m} · I. Here, k _m is a value specific to each motor 26 by a torque constant. Therefore, the control unit 32 can obtain the torque T output from the motor 26 based on the drive current I measured by the current measurement unit 47 of the motor power supply 33.

  As described above, the amount of continuous current supplied to the DC motor and the generated torque are in proportion to each other within the allowable temperature and allowable rotation speed ranges. That is, if the continuous current amount is increased, the torque is also increased. However, as the amount of current increases, the amount of heat (joule heat or the like) generated in the motor coil (or rotor) also increases. When a current (overcurrent) exceeding the maximum continuous current according to the design specification for each motor is passed for a long time, the maximum allowable temperature set in advance is exceeded, the coil burns out, and the motor is damaged. Here, the maximum continuous current that drives the motor within a range not exceeding the maximum allowable temperature without causing any damage to the motor is referred to as a rated current.

  However, if the coil is in the range of the maximum allowable temperature or less, it is possible to drive the motor by passing an overcurrent in a short time. The driving time due to the overcurrent of the motor is determined by the winding thermal time constant of each motor. This driving time is, for example, about several seconds to about 1 minute. Therefore, a pulse voltage having an on-time and an off-time is selected as a drive power source that can easily adjust the application time for driving the motor. The pulse voltage waveform need only have an off time, and does not necessarily have to be a rectangular wave having an accurate edge.

  In FIG. 2, the vertical axis represents the ratio of maximum peak current Ion / maximum continuous current In, and the horizontal axis represents the motor drive ratio. That is, the numerical value on the vertical axis indicates how many times the current flowing in the coil is the maximum continuous current. Here, a state where a current value of 1 to 5 times flows is shown. The horizontal axis indicates the rate (duty ratio) at which the motor is driven per unit time T.

  Further, as shown in FIG. 3, in the duty ratio of the pulse voltage serving as the drive power supply, the energization time ton for driving the motor (voltage application) per unit time (cycle time) T of the pulse to be applied, and the motor drive (non-drive) The non-energization time toff when no voltage is applied. For example, if the duty ratio is 0.6, the time ton is 60%, and the remaining 40% time is the non-driven time toff.

  These characteristics are numerical values set with the maximum allowable temperature as an upper limit. In FIG. 2, for example, when a peak current Ion twice the maximum continuous current In is passed, the duty ratio should be 0.25. Thus, it is possible to drive continuously without exceeding the maximum allowable temperature. The time ton or the peak current Ion is set as follows.

T = ton + toff
ton / T = (In / Ion) ² (1)
Ion = In (T / ton) ^1/2 (2)
However, ton: on time, toff: off time, T: cycle time, In: maximum continuous current, and Ion: maximum peak current.

  As described above, since the driving current flowing through the motor and the generated torque are in a proportional relationship, by making the peak current Ion larger than the maximum continuous current In, a torque larger than the torque generated at the time of the maximum continuous current In can be obtained. Can be generated. That is, when a continuous current is supplied to the small motor 26 and the motor is normally used, the bent portion generates a load corresponding to the bending amount (or bending angle). This relationship is measured in advance and a correspondence table is created. Therefore, if the amount of bending or the bending angle is known, the magnitude of the load acting on the bent portion can be known. That is, the load is known by the amount of bending.

  If the torque generated by the motor is less than this load, even if it is further bent, the motor stops at that position. If a pulse voltage having a peak current Ion larger than the continuous current (normally the maximum continuous current) In at that time is applied in this stop state, the movement is started again. However, such driving by applying a pulse voltage is slower in bending operation than driving by continuous current. That is, the operation response is reduced. However, in the stop state, that is, switching to the application of the pulse voltage is a state in which it is bent even in the movable range of the curve, so the responsiveness in the moving speed is not so important, and the practical range. Is within.

[Switching timing]
Next, the timing at which the continuous current in the drive power source supplied (energized) to the motor 26 is switched to the pulse current will be described.
The first switching timing is a time point when the bending operation of the bending portion 14 stops during the bending operation.
As the first timing, when the bending operation of the bending portion 14 is stopped by a load, a peak current Ion based on a torque that becomes a driving force necessary for further performing the bending operation is obtained. The motor power source 33 generates a pulse driving power source having a duty ratio (time ton-toff) obtained from this value. When the bending operation stops, the motor power source 33 immediately switches from the driving power source with the (maximum) continuous current In to the pulse driving power source with the pulse current and supplies the motor 26 with the switching power source. At this time, the motor 26 maintains the maximum allowable temperature or less.

The second switching timing is the time when the torque output from the motor 26 exceeds a preset torque threshold before the bending operation of the bending portion 14 stops.
With the correspondence table described above, the load at that time is known from the amount of bending (bending angle) of the bending portion 14. Necessary torque can be obtained for this load. Therefore, a torque that can be generated by the maximum continuous current energized to the motor 26 is obtained in advance, and a value close to this torque or less is set as a torque threshold. When the bending operation is performed at the bending portion, the torque of the motor 26 increases with the increase in the load generated by the bending portion at that time, and eventually reaches the torque threshold.

  Actually, as the second switching timing, the torque generated by the motor 26 is calculated by the torque calculation unit 44 when the bending unit is bent. When the calculated torque exceeds the set torque threshold, the duty ratio (time ton) obtained by referring to FIG. 2 from the value of the peak current Ion based on the torque required for the subsequent bending operation -Toff) is generated by the motor power source 33. The motor power source 33 switches from a driving power source with a maximum continuous current to a driving power source with a pulse current (pulse voltage) and supplies (energizes) the motor 26. At this time, the motor 26 maintains the maximum allowable temperature or less. If the bending operation by the motor 26 is stopped after switching to the driving power source by the pulse current exceeding the torque threshold, the first switching timing may be shifted to.

As a third switching timing, a bending amount threshold (or bending angle) in which the bending amount (or bending angle) of the bending portion detected during the bending operation is set in advance before the bending operation of the bending portion 14 is stopped. When the threshold value is exceeded.
As described above, the bending amount is estimated from the resistance value of the potentiometer 34 measured by the resistance value measuring unit 42. By design or actual measurement, a load generated in the bent portion 14 is obtained from the amount of bending, and a torque capable of bending the bending portion can be obtained with respect to this load. Therefore, if the torque that can be generated by the maximum continuous current that is energized to the motor 26 is obtained and the above relationship is traced in reverse, the bending amount of the bending portion 14 with respect to this torque can be obtained. Is set to the curvature amount threshold.

  Actually, the third switching timing estimates the current bending amount of the bending portion 14 from the resistance value acquired by the resistance value measuring unit 42 when the bending portion is being bent. Then, when the bending amount increases due to the bending operation and exceeds the bending amount threshold value, the driving power source is switched from the continuous current driving power source to the pulse driving power source and supplied (energized) to the motor 26 as described above. At this time, the motor 26 maintains the maximum allowable temperature or less.

  As the fourth switching timing, it is assumed that the load generated by the bending portion detected during the bending operation exceeds a preset load threshold before the bending operation of the bending portion 14 stops.

  Substantially the same as the second switching timing. Here, it is assumed that the relationship between the bendable load and the torque in the bent portion is known by design or actual measurement. First, the torque that can be generated with the maximum continuous current that is supplied to the motor 26 is obtained. A load corresponding to this torque, that is, a load at which the bending portion can be bent with respect to this torque is defined as a load threshold.

  Actually, the fourth switching timing estimates the bending amount of the bending portion 14 from the resistance value of the potentiometer 34 measured by the resistance value measuring portion 42 when the bending portion is being bent. And the load which acts on a bending part is calculated | required from the bending amount. When the calculated load exceeds the load threshold due to the increase in the amount of bending, the driving power source is switched from the continuous current driving power source to the pulse driving power source and supplied (energized) to the motor 26 as described above. At this time, the motor 26 maintains the maximum allowable temperature or less.

The fifth switching timing is a time when the operation amount in the UD direction of the operation switch 30 exceeds a preset threshold value.
When the operation amount of the operation switch 30 exceeds a preset operation amount threshold, the power is switched from the power source with the maximum continuous current to the power source with the pulse current (pulse voltage) and supplied to the motor 26. The load applied by the bending amount (or bending angle) of the bending portion 14 by this operation amount is obtained in advance, and the duty ratio (time ton-toff) obtained from the value of the peak current Ion based on the torque corresponding to the load. ) Is generated by the motor power source 33.

  As the sixth switching timing, an operator may provide a changeover switch or the like, select as appropriate, and switch from the driving power source with the maximum continuous current to the driving power source with the pulse current (pulse voltage) to supply to the motor 26. Good.

  According to the drive control of the endoscope apparatus equipped with the above-described small motor, the drive current larger than the maximum continuous current is intermittently supplied under the condition that the motor 26 maintains the maximum allowable temperature or less, and the maximum continuous By generating a torque that is greater than the torque generated by the current, the upper limit of the bending operation possible range of the bending portion can be increased. Therefore, the motor can be made smaller (lower rated) than the conventional motor driven by the maximum continuous current, and the operation part of the endoscope body can be made smaller and lighter.

[First Embodiment]
Next, a first embodiment of an endoscope system including a small motor by the control described above will be described. FIG. 4 is an overview diagram showing a configuration example of an endoscope system driven by a small motor. In addition, about the structural part of this embodiment, the same reference number is attached | subjected to the same part as the structural part of the endoscope system mentioned above, and the description is abbreviate | omitted. In the present embodiment, the bending portion 14 described above corresponds to the second bending portion 14. In the present embodiment, the motor is driven in conjunction with the operation of an angle knob, which will be described later, and no switch for instructing driving to the motor itself is provided.

  The endoscope body of the present embodiment has a configuration having two first and second curved portions. The first bending portion 11 disposed on the distal end side of the insertion portion manually drives the two provided angle knobs 12 and 13. The second bending portion 14 connected to the first bending portion 11 performs a driving operation by the electric power of the motor 26 described above. That is, in the present embodiment, the first bending portion 11 is bent in synchronization by manually rotating the angle knobs 12 and 13. After the rotation of the angle knobs 12 and 13 reaches a predetermined position, that is, the threshold angle, the first bending portion 11 maintains the current bending state, and the second bending portion 14 starts a bending operation. To do. Details will be described below.

FIG. 5 shows a conceptual configuration of the operation unit 8 and the insertion unit 9 for the bending operation in the present embodiment.
The first bending portion 11 and the second bending portion 14 in the insertion portion 9 are respectively bent tubes (first and second bending drive mechanisms) 11a, 14a formed of a plurality of known bending pieces, and the bent tubes 11a, 14a. A blade disposed on the outside of the blade and a skin disposed on the outside of the blade.

  For example, four angle wires 21 (U, D, R, L) are fixed to the distal end (one end) of the bending tube 11a of the first bending portion 11 corresponding to each bending direction of the first bending portion 11. Has been. Among these, the rear end (the other end) of the angle wire 21 (U, D) that is bent in the vertical direction is wound around and fixed to the first drum 23 inside the operation unit 8. Further, the angle wires 21 (R, L) for bending the first bending portion 11 in the left-right direction are wound around the second drum 24 and fixed.

  A first angle knob (bending operation input unit) 12 that rotates the first drum 23 and a second angle knob 13 that rotates the second drum 24 are disposed outside the operation unit 8. The first and second drums 23 and 24 and the first and second angle knobs 12 and 13 are arranged on the same axis.

  The first angle knob 12 and the first drum 23 rotate in synchronization, and the first drum 23 and the first angle knob 12 rotate by the same angle. Similarly, when the second angle knob 13 is rotated, the second drum 24 and the second angle knob 13 are rotated by the same angle. In the present embodiment, the bending tube 11a, the wire 21, the first drum 23, and the first angle knob 12 form a first bending drive mechanism that bends the first bending portion 11.

  With such a configuration, by rotating the angle knobs 12 and 13, the first bending portion 11 is set as the first and second directions in the up / down (UP / DOWN) direction (indicated by U and D in FIG. 5), and the first Curved in three directions and a left and right (RIGHT / LEFT) direction (indicated by R and L in FIG. 5) as a fourth direction.

  Next, the two angle wires 22 (U ′, D ′) for bending the second bending portion 14 in the U direction and the D direction are wound around the third drum 25 inside the operation portion 8 and fixed. Yes. The third drum 25 is provided with a motor 26 and an encoder 27 that detects the rotation amount (rotation angle) ω of the motor 26. The motor 26 generates a driving force for bending the second bending portion 14 and bends it in the vertical direction. In the present embodiment, the bending tube 14 a, the wire 22, the third drum 25, and the motor 26 constitute a second bending drive mechanism that bends the second bending portion 14.

  In the present embodiment, the position where the first bending portion 11 is straight is defined as the initial position (neutral position) of the first angle knob 12, and the position where the second bending portion 14 is straight is defined as the initial position of the motor 26. (Neutral position).

  The first drum 23 is provided with a knob position detection potentiometer (input amount detection unit) (not shown) as a detection unit for detecting the rotational position of the first drum 23. The knob position detecting potentiometer is set to zero at the initial position of the angle knob 12. This knob position detecting potentiometer detects the rotation amount of the first drum 23, that is, the rotation position (rotation angle) ψ of the angle knob 12. Therefore, the knob position detecting potentiometer can estimate the rotation amount ψ of the first drum 23 from the bending operation input amount detected by the bending operation amount input to the angle knob 12. Since the rotation amount ψ substantially corresponds to the bending amount (bending angle) η in the U direction and D direction of the first bending portion 11, the bending portion 11 is bent in the U direction and D direction from the rotation amount of the angle knob 12. The quantity (bending angle) can be estimated.

  In the present embodiment, when the bending amount (bending angle) of the first bending portion 11 detected by the knob position detection potentiometer exceeds a preset amount (bending amount or bending angle), the first bending portion. The second bending portion 14 is switched to the bending operation while maintaining the eleven bending state. When the second bending portion 14 returns to the initial position, the operation returns to the switching operation of the first bending portion 11.

In such a configuration, the first drive control of the second bending portion in the first embodiment will be described with reference to the flowchart shown in FIG.
Here, although explanation is omitted, in the first bending portion 11, when the observation is performed beyond the bending range defined in advance based on the estimated bending angle, the bending operation of the second bending portion 14 is performed. By switching, the driving current I by the continuous current In is energized and the bending operation is continued.

  First, with respect to the second bending portion 14, the bending amount estimated from the operation amount in the UD direction by the drum 25 obtained from the resistance value of the potentiometer 34 measured by the resistance value measuring portion 42, that is, the bending angle from the initial position ( Angle B) is acquired (step S1). Next, the acquired angle B is compared with the preset set angle X described above as the switching timing (step S2). If the angle B is larger than the set angle X (YES), the motor 26 outputs. It is determined that the torque is the same as or close to the load at the second bending portion 14, and the power supplied to the motor 26 is changed from the peak current larger than the continuous current In (In = drive current I). Switch to the pulse power supply. At this time, the drive current I applied to the motor 26 is set to the above-described peak current Ion so as to obtain a torque corresponding to the angle B (step S3). Further, the energization time ton is set so that the maximum allowable temperature becomes the upper limit for the temperature rise accompanying the application of the peak current Ion, and the motor 26 is energized (step S4). At the same time, the motor 26 is intermittently stopped for the non-energization time toff corresponding to the cycle time T, the temperature of the motor coil is cooled, and the temperature rise is suppressed (step S5).

  If the angle B is equal to or smaller than the set angle X in the comparison in step S2 (NO), the driving with the continuous current In is continued. Here, the driving current I of the motor 26 is updated to the continuous current In that generates the torque required at the angle B (step S6). Then, the updated drive current I is energized to drive the motor 26 (step S7).

  Further, it is determined whether or not the bending operation or the like of the first and second bending portions by the operator is continued (step S8). If the bending operation is continued (YES), the process returns to step S1 and the operation is continued. If it is not done (NO), the current state is maintained and the process waits, or if the observation is finished, the process is finished through a predetermined sequence process.

  According to the first drive control described above, the bending operation is continued by switching from the first bending portion 11 to the bending operation of the second bending portion 14 and energizing the drive current I by the continuous current In. When the bending angle of the second bending portion 14 sequentially detected in the bending operation exceeds a preset angle X, which is a predetermined threshold value, the driving power source is driven by the continuous current, that is, the driving power source by the pulse current. Can be switched to. In other words, the drive power supply by the pulse current (pulse voltage) is changed from the drive power supply by the maximum continuous current so that the torque generated by the motor 26 exceeds the load generated by the bending of the first bending section 11 and the second bending section 14. To be supplied to the motor 26. At this time, the motor 26 maintains the maximum allowable temperature or less.

  Therefore, according to the present embodiment, in the bending operation of the second bending portion 14, a driving current larger than the maximum continuous current is intermittently supplied to the motor 26 to generate a torque greater than the torque generated by the maximum continuous current. By doing so, the upper limit of the bending operation possible range of the bent portion can be increased. Further, by applying the bending operation by the motor 26 to the second bending portion 14 that is used as an auxiliary, even if the operation response at the moving speed is reduced due to switching of the pulse power supply, within the practical range in the endoscope apparatus. Yes, the movable range can be expanded and a wider range can be observed.

  In this example, the example in which the second bending portion 14 is bent after the first bending portion 11 is bent has been described earlier, but the present invention is not limited to this example. You may perform drive control which curves the 1st bending part 11, after bending the bending part 14 and making it move to an observation position roughly. Further, the bending operation of the first bending portion 11 and the bending operation of the second bending portion 14 can be combined, and drive control can be performed sequentially or simultaneously. Even in these drive control procedures, a drive current larger than the maximum continuous current is intermittently supplied to the motor 26 of the second bending portion 14 to generate a torque greater than the torque generated by the maximum continuous current. The upper limit of the bendable range of the bent portion can be increased.

  Next, the second drive control of the second bending portion in the first embodiment will be described with reference to the flowchart shown in FIG. In the second drive control, the same step numbers are assigned to the same control steps as the first drive control described above, and the description is simplified.

  In the second drive control, in the drive control described above, depending on the shape of the tube hole in which the insertion portion of the endoscope apparatus is inserted, the second drive control may be rounded to form a loop shape. Even in this case, the bending drive may be inoperative. In this case, the current bending angle of the second bending portion is regarded as a temporary bending angle (Y: Y> X) and is updated, and a pulse current is applied to drive.

  First, the bending angle (angle B) of the second bending portion 14 is acquired, and the acquired angle B is compared with the preset set angle X described above as the switching timing (steps S1 and S2). In this comparison, if the angle B is larger than the set angle X (YES), the power supplied to the motor 26 is set to a peak current larger than the continuous current In and the energizing time ton, and the motor 26 is energized and de-energized. The motor 26 is driven to stop intermittently for the time toff (steps S3, S4, S5).

  Next, the current bending angle (angle A) of the second bending portion 14 is acquired (step S9), and the difference of the angle A from the angle B is taken (step S10), and there is no difference (= 0). In this case, the angle B is set to a temporary bending angle (Y), and the process returns to step S2 (step S11). Thereafter, the angle B is set as a provisional bending angle (Y), compared with the set angle X, and the routine is continued. On the other hand, when the difference of the angle A from the angle B is positive (> 0), the process returns to step S1 to acquire the bending angle (angle B) of the second bending portion 14 again.

If the angle B is equal to or smaller than the set angle X in the comparison in step S2 (NO), the driving with the continuous current In is continued and the torque required for the driving current I of the motor 26 at the angle B is generated. The continuous current In is updated (step S6), the updated drive current I is energized to drive the motor 26 (step S7), and the process proceeds to step S9.
[Second Embodiment]
Next, in the present embodiment, the bending operation input unit manually driven by the first angle knob 12 and the second angle knob 13 in the second embodiment described above is replaced with a motor, and the bending operation input unit is electrically driven by a switch operation. It is the composition.

FIG. 8 shows a conceptual configuration of the operation unit 8 and the insertion unit 9 for the bending operation in the present embodiment. In addition, about the structural part of this embodiment, the same reference number is attached | subjected to the same part as the structural part of the endoscope system mentioned above, and the description is abbreviate | omitted.
In this embodiment, instead of the two angle knobs in the first embodiment described above, the first bending portion is replaced with two motors, and the motor is also used in the second bending portion 14. Is an endoscope system that drives the motor in conjunction with the bending operation of the first bending portion.

  This embodiment is not basically configured so that the operator grips and operates the endoscope body, but the endoscope body is separately attached to the arm, and the operator is separated from the endoscope body. A bending operation is performed by remote control using a body remote control switch (not shown).

The two motors 51 and 53 of the first bending portion are motors having the same configuration as that of the motor 26, and are basically driven with high responsiveness by a driving power source using a continuous current.
The first bending drive mechanism that bends the first bending portion 11 and the second bending drive mechanism that bends the second bending portion 14 in this embodiment are the same as those in the first embodiment described above.

In the present embodiment, the bending amounts (rotation amounts) of the first bending portion 11 and the second bending portion 14 are bent from the rotation amounts ω of the motors 51, 53, and 26 detected by the encoders 52, 53, and 27, respectively. It is estimated based on the rotation amount of the drive mechanism.
According to this embodiment, the same effects as those of the first embodiment are achieved. Furthermore, since all the driving of the bending operation is performed by the motor, there is no sense of incongruity combining manual operation and electric operation in the bending operation, and continuous operation using only the operation switch can be performed.

  DESCRIPTION OF SYMBOLS 1 ... Endoscope system (medical apparatus), 2 ... Endoscope main body, 3 ... Light source, 4 ... Video processor, 5 ... Monitor, 6 ... Connector, 7 ... Universal cord, 8 ... Operation part (endoscope main body) DESCRIPTION OF SYMBOLS 9 ... Insertion part, 11 ... 1st bending part, 12 ... 1st angle knob, 13 ... 2nd angle knob, 14 ... bending part (2nd bending part), 15 ... observation optical system connector, 16 ... tip hard part , 17 ... tubular portion, 18 ... imaging unit, 19 ... light guide, 21, 22 ... angle wire, 23, 24, 25 ... drum, 26 ... motor, 27 ... encoder, 31 ... motor drive circuit, 32 ... drive control unit (Control unit), 33 ... motor power supply, 34 ... knob position detection potentiometer (detection unit), 41 ... CPU, 42 ... resistance value measurement unit, 43 ... count processing unit, 44 ... torque calculation unit, 45 ... threshold input unit (Setting part), 46...憶部, 47 ... current measurement unit, 48 ... voltage setting unit.

Claims (8)

An insertion part that is arranged on the distal end side where the observation optical system is provided and can be inserted into the tube hole,
A bending drive mechanism for bending the bending portion to a desired bending angle;
A bending instruction input unit that instructs the bending unit to have a bending amount that suggests a desired bending angle by the bending driving mechanism;
A driving unit that generates a driving force for bending the bending driving mechanism in accordance with an instruction from the bending instruction input unit;
Any of the bending amount, the load, and the driving force obtained with the bending operation is set to a threshold value that is set by associating a load that acts on the bending portion caused by the bending amount and a driving force that is generated by the driving unit. When the power reaches, the drive power source by the continuous current that is energized to the motor has a peak value that exceeds the maximum continuous current that can be driven within the range of the maximum allowable temperature in the drive unit, and the drive unit A control unit that switches to a pulse power supply by a pulse current including a non-application time for maintaining the maximum allowable temperature or less in a cycle, and energizes and drives the motor;
An endoscope apparatus comprising:   When the load acting on the bending portion that performs the bending operation exceeds the driving force that is the threshold generated by the driving portion, the control unit supplies the driving power source by the continuous current to the driving force that exceeds the load. The endoscope apparatus according to claim 1, wherein the endoscope is switched to the pulse power source having the peak value to be generated.   The controller has the pulse having the peak value that generates a driving force exceeding the load when the bending amount of the bending portion exceeds a bending amount threshold value that is the threshold value. The endoscope apparatus according to claim 1, wherein the endoscope apparatus is switched to a power source.   The control unit has the peak value that has the peak value that generates a driving force exceeding the load when the bending angle of the bending portion exceeds a bending angle threshold value that is the threshold value. The endoscope apparatus according to claim 1, wherein the endoscope apparatus is switched to a power source.   When the driving force generated by the driving power source used for the bending operation of the bending portion exceeds the driving force that is the threshold generated by the driving portion that is energized with the maximum continuous current, The endoscope apparatus according to claim 1, wherein a driving power source by a continuous current is switched to the pulse power source having the peak value that generates a driving force exceeding the load.   When the load acting on the bending portion that performs the bending operation exceeds a load threshold value that is the threshold value, the control unit causes the driving power source by the continuous current to generate the driving force that exceeds the load. The endoscope apparatus according to claim 1, wherein the endoscope apparatus is switched to the pulse power supply.   The control unit has the peak value that causes the driving power source by the continuous current to generate a driving force exceeding the load when an operation amount with respect to the bending instruction input unit exceeds an operation amount threshold value serving as the threshold value. The endoscope apparatus according to claim 1, wherein the endoscope apparatus is switched to the pulse power source. An insertion portion having a first bending portion provided with an observation optical system at the tip and a second bending portion connected to the first bending portion, the insertion portion being insertable into the tube hole from the tip;
A first bending drive mechanism having a bending operation input section for bending the first bending section;
A second bending drive mechanism that is bent by a motor mounted with the second bending portion;
A detecting unit that detects that a bending amount of the first bending unit exceeds a preset amount when the first bending unit is bent by the first bending drive mechanism;
When the detection result by the detection unit exceeds the set amount of the bending amount of the first bending unit, it is switched to the bending operation of the second bending unit,
Any of the bending amount, the load, and the driving force obtained with the bending operation is set to a threshold value that is set by associating a load that acts on the bending portion caused by the bending amount and a driving force that is generated by the driving unit. When the power reaches, the drive power source by the continuous current that is energized to the motor has a peak value that exceeds the maximum continuous current that can be driven within the range of the maximum allowable temperature in the drive unit, and the drive unit A control unit that switches to a pulse power supply by a pulse current including a non-application time for maintaining the maximum allowable temperature or less in a cycle, and energizes and drives the motor;
An endoscope apparatus comprising:

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